Glossary extracted starting with automatic seeds, with PTM for the domain phy and language EN

solid	One characteristic of a solid is that it might be hard
arc second	abbreviated arcsec
density	the amount of matter contained within a given volume
oxygen	Hence its name CNO-cycle
marian flag	One of a number of flags – most often a bicolour of blue and white - that symbolizes veneration of the Virgin Mary in the Christian tradition (see also ‘Christian flag 1)' and ‘religious flag').
cgms	Coordination Group for Meteorological Satellites
entropy	Measure of the disorder of a system.
angular size	A measure of the apparent size of an object in the sky, measured in angles.
parent body	The larger interplanetary object of which a meteorite is a fragment.
enzyme	A protein that causes or accelerates chemical reactions at a lower temperature than those reactions would normally occur.
equation of time	[E, EoT] the time difference between Local Apparent Time (apparent solar time) and mean solar time at the same location
luminosity	The total amount of energy emitted per second by an astronomical source.
iter	international thermonuclear experimental reactor - being built in southern France
eso	European Southern Observatory.
induction	A logical method for drawing a broad conclusion from a limited set of observations or experiments
mars	4th planet
toa	Top of Atmosphere
molarity	The number of moles of solute (the material dissolved) per liter of solution
anorthosite	Granular igneous rock usually comprised of soda-lime feldspar.
specific gravity	The specific gravity is a comparison of the mass of a substance to the mass of water with the same volume
conservation of matter	Name of the concept that explains how mass cannot be created or destroyed during a chemical reaction.
hour	A division of time equal to sixty minutes, 3600 seconds, or 1/24 of a solar day.
earth	to the
cosmological principle	The principle, which states, that the Universe is homogeneous and isotropic on large scales
prare	Precise Range and Range-rate Equipment
polarised light ~	a gnomon-less dial which detects the orientation of the polarised skylight
spectrometer	An instrument for tracing the intensity of a spectrum at different wavelengths; the result is a graph.
twilight	The period of decreasing sky brightness after sunset, or of increasing sky brightness before sunrise
magnitude	The degree of brightness of a star or other object in the sky according to a scale on which the brightest star has a magnitude -1.4 and the faintest visible star has magnitude 6
molar	An term expressing molarity, the number of moles of solute per liters of solution.
taloned	See ‘armed’ (also ‘membered’).
visible spectrum	The small range of the electromagnetic spectrum that human eyes percieve as light
fan’s flag/pennant	See ‘sports flag 2)’.
declining ~	a vertical dial which does not face any of the cardinal points of the compass
admiral's flag	See ‘flag of command 1)'.
quarter the arms	(v) The heraldic phrase used when a shield or banner of arms, which was formerly impaled, is divided into four, with the previously impaled arms displayed in opposing quarters – see ‘impaled' and compare with ‘quartered 1)'.
crt	Cathode ray tube video display device.
kamon	See ‘mon 2)’.
great decliner	usually indicates a declining dial which nearly, but not quite, faces E or W
uncertainty principle	Heisenberg uncertainty principle
template flag	See ‘archivexillum’.
strontium	Symbol:"Sr" Atomic Number:"38" Atomic Mass: 87.62amu
dcs	Data Collection System
aerolite	An aerolite is a meteorite that is consists mostly of stony matter.
uranium	Symbol:"U" Atomic Number:"92" Atomic Mass: 238.03amu
ecclesiastic flag	See ‘Christian flag 1)’.
helium burning	The fusion of helium into carbon through the triple-alpha process.
laser	Light Amplification by Stimulated Emission of Radiation
canonical ~	the seven times of the day (as opposed to time periods) used to define the services or divine offices in the medieval church
vertical pennant	1) Generically, any pennant designed to be hung vertically (see also ‘pennant 2)')
electromagnetic force	One of the four fundamental forces of the universe.
earth	, we create electrical energy for our homes at power plants, we turn gasoline into energy to make our cars run, and we eat foods so that our bodies have energy to move
force	A reaction between two or more bodies which tends to affect the physical relationship between them, such as their motion or position.
helium	Symbol:"He" Atomic Number:"2" Atomic Mass: 4.00amu
earth	yet.
seds	Students for the Exploration and Development of Space
element	A substance that contains only one kind of atom
vertical ~	any dial in which the dial plate is vertical.
empale	See ‘impale’.
naiant	See ‘appendix V’.
cell membrane	A structure, formed from bilayers of lipids, that seperates the inside of the cell from the outside, or seperates one part of a cell from another.
star	A self-luminous object that shines through the release of energy produced by nuclear reactions at its core.
cavus pl. cavi	Hollows or irregular steep-sided depressions, usually in arrays or clusters.
dendritic habit	A dendritic habit describes the shape of a large group of crystals that looks like the branching of veins or a plant.
ius	Inertial Upper Stage.
saltirewise	See ‘in saltire’.
galactic center	The dense, bright center of a galaxy
propulsion	The act of moving an object and maintaining its motion.
electromagnetic force	A fundamental force that influences anything which carries a charge
ellipse	an ellipse is an oval shape
carbonaceous chondrite	a type of primitive chondrite with evidence of nebular processes.
antipodal point	the point that is directly on the opposite side of the planet; e.g., the Earth's north pole is antipodal to its south pole.
ecliptic plane	The plane of the Ecliptic, in space
meteor shower	large number of meteors burning upon entering Earth?s atmosphere, occurring when Earth?s orbit passes through debris from a comet.
saint george-type cross	See ‘cross 1)’ (also ‘St George’s Cross 3)’).
gay pride flag	See 'rainbow flag 1)'.
calendar	a system for counting days and defining the date.
stellar association	See OB association.
main ordinaries	See ‘ordinary’.
direct motion	eastward motion in the sky
kelvin	a temperature scale used in sciences such as astronomy to measure extremely cold temperatures
galaxy	and the
insoluble	An insoluble substance is one that is not able to dissolve in another substance
octaval ~	a time system with the period of daylight divided into eight hours
unit colour	See ‘colour 2)’ and ‘colours 2)'.
hour point	a point on the dial plane indicating the crossing of the gnomon's shadow at a particular time
emission line	Very narrow wavelength intervals in which atoms emit light.
in base	The heraldic term used when a charge or charges appear in the lower part of a shield, banner of arms or flag that is otherwise undivided – see ‘base 1)’ (also ‘abased', ‘banner of arms', and ‘shield’).
potential energy	Stored energy, or energy with the potential to do work
geronny	See ‘gyronny’.
equatorial plane	The plane that passes through the centre of a body and is perpendicular to that body's axis of rotation.
volatile	A volatile compound has a lower boiling point than surrounding compounds
last quarter	a phase of the Moon or other planetary object when it is exactly half illuminated as seen by the observer; occurs between the full and new phases
earth	and
day	the period for one rotation of the Earth
pulse rate	The number of times a heart beats per minute in a person's body.
photosynthesis	Process that converts sunlight into stored chemical energy, essential for the proliferation of advanced forms of life.
gravitation	The mutual attraction of all masses in the universe.
direct rotation	Rotation in the same direction as the orbital motion of an object.
rima	a fissure.
pan-slavic/slav colours	The blue, white and red originally adopted by the Slavic peoples during their struggles for independence from the Ottoman and Habsburg empires, and derived from the national flag/civil ensign of the then Russian Empire - but see note below (also ‘core flag’, ‘difference’, 'flag family', ‘pan-African colours’ and ‘pan-Arab colours’ above)."
greenhouse effect	The process in which heat is allowed to enter the atmosphere of a planet but cannot escape.
jim lovell	Commander of Apollo 13.
hemispherium	an ancient dial with the dial surface formed by a hemisphere hollowed into a horizontal (or occasionally vertical) stone face
zenith	The point directly above an observer on the celestial sphere, so that a line to it is at right angles to the plane of the horizon.
black hole	A region of space containing so much matter in such a small space that its enormous gravity will not allow even light to escape
singularity	The hypothetical condition of a black hole
emulsion	A coating on photographic plates that reacts to light.
limb	part of an astrolabe, it is the circular ring with a scale of hours and degrees
gravity	A force that pulls two or more things together.
cantonal flag	The sub-national flag of a territorial division within a country, particularly if that subdivision is is called a canton - e.g
teutonic cross	See ‘cross-potent’ in ‘appendix VIII’.
kilometer	103 meter.
life	A condition of matter that makes it able to take in food and convert it to energy, grow, and make copies of itself
vertical tricolour	See ‘tricolour 1)’ and ‘tricolour 2)’.
pleiades	An open cluster (M45) in Taurus known as the Seven Sisters.
imperial arms	The arms that represent an empire and its ruler - a type now entirely obsolete - but see ‘imperial emblem' (also ‘imperial standard(s) 1)' and ‘royal arms').
julian year	a unit of time defined as exactly 365.25 days
raven flag	The flag considered by some sources to have been carried by Viking raiding parties up until the 11th Century, and to have been carried by the Normans at the Battle of Hastings (1066) (see also ‘Bayeux tapestry').
call sign hoist	A hoist of signal flags displaying the international call sign of a civil or naval vessel – but see ‘make her number' (also 'address group', 'call sign', ‘signal hoist', ‘international code of signal flags’, ‘pendant number’ and ‘signal flag’).
henry's law	Gases are able to be dissolved in solvent just like solids and liquids
heat	A form of energy that can be transferred from one place or object to another when there is a difference in temperature.
ablation	Ablation is a cooling process in which heat is carried away from an object (like a falling meteorite) as the flow of air blows away the hot, melted or vaporized outer layers of the object
celestial globe	A globe showing the relative positions of stars.
lens	A see-through object, usually made of glass, that can bend light.
analemma	(pron
protactinium	Symbol:"Pa" Atomic Number:"91" Atomic Mass: 231.04amu
patera	A shallow crater with a complex, scalloped edge.
quinas	The Portuguese term for the five plates or discs with which the five blue escutcheons on the national arms of Portugal are charged (see also ‘disc' and ‘plates').
kilogram	The SI unit of mass.
gardamano	See ‘handguard’.
ephemeris	(pron
constellation	A group of stars that make a shape (they look like connect-the-dots) - usually named after mythological characters, people, animals and things.
theory	A body of hypotheses, often with mathematical backing and having passed some observational tests; often implying more validity than the term hypothesis.
silicon chip	A small crystal of silicon semiconducter used in electronics.
caltrap	The heraldic term for a three or four-armed (usually but not invariably faceted) figure that represents an implement of war consisting of four spikes which, when thrown on the ground, always has one point facing upwards, and designed to injure horses – a caltrop, calthrop, cheval-trap or galtrap (see also ‘faceted').
meteoroid	A meteoroid is a small rock or particle of debris in our solar system
helioseismology	The study of the interior of the Sun.
yale catalogue	See Bright Star catalogue.
irregular galaxy	A galaxy of amorphous shape
ion	A small particle which has a magnetic charge.
naval ensign	See under ‘ensign’.
ncep	National Center for Environmental Prediction
mineral transparency	Transparency is a quality of how much light you can see through a substance
lac	Local Area Coverage
earth	, which are caused by the
dithering	A process used by astronomers to correct for the effects of bad pixels and cosmic rays in CCD images
altitude ~	{or elevation ~} any dial which uses the sun's altitude, rather than its azimuth, for indicating the time
breccia	A rock made from mineral fragments cemented together by the heat of meteoroid impact.
direct motion	Motion which is in the usual direction
soft x-ray	primarily because of difference in observation techniques.
argon	One of the noble (inert) gases.
celestial equator	The imaginary line dividing the northern and southern hemispheres of the celestial sphere
ecliptic co-ordinates	A system of celestial co-ordinates that uses the ecliptic as the reference plane and the First Point of Aries as the reference direction
first quarter	a phase of the Moon or other planetary object when it is exactly half illuminated as seen by the observer; occurs between the new and full phases
noble gas	The Noble Gases are the all of the elements in the furthest right column of the periodic table
diurnal	Daily.
ergol	Homogenous substance used, alone or with other substances in the composition of a propellant.
weight	A measure of the force due to gravitational attraction.
declination	A component of the coordinate system used to designate positions on the celestial sphere
ball of difference	In British Royal Navy usage and some others, the disc or discs of distinction carried by the command flags of those flag officers who rank below the grade of full admiral (see also ‘boat flag 3)’, ‘disc’, ‘flag of command 1)’, ‘flag officer 1)’ and ‘flag officer 2)’.
iron	what
helium	what
vis	Visible channel
wolf-rayet stars	are hot, blue giants
meteorite	mass of rock or metal that has survived friction of Earth?s atmosphere to reach the surface.
photon	A particle of light composed of a minute quantity of electromagnetic energy.
triple point	A temperature point at which a substance can be either a solid, liquid, or gas
binary	A system of two stars that revolve around a common center of gravity.
ac	Alternating current.
retrograde	westward motion in the sky
kirkwood gaps	regions in the main belt of asteroids where few or no asteroids are found
earth	, and thousands litter the surface of the
solar wind	streams of gas particles flowing out from the sun
equinox	Literally "equal night"
mct	Mission Control Team, Section 391 project operations.
julian date	the interval of time in days and fraction of a day since 1 January 4713 BC, Greenwich noon.
hemisphere	Half of a sphere
filtrate	Filtrate is the solid substance remaining after you remove the liquid of a solution
meteor	A short streak of light caused by a meteoroid entering the Earth's upper atmosphere
julian calendar	the calendar system introduced by Emperor Julius Caesar and devised by the Greek philosopher (and court astronomer of Egypt) Sosigenes
offset	Not in quite the same place.
commander	often the pilot
atom	, consisting of positively charged protons and electrically neutral neutrons
king’s colour	See ‘colour 2)’ and ‘colours 2)’.
caloris basin	An impact basin 1300km across, the largest on Mercury
bolometer	A device which measures the energy of all of the radiation which falls on it, regardless of the wavelength or visibility of the radiation.
decibel	dB, an expression of ratio (see dB, above)
stellar wind	The ejection of gas from the surface of a star
azimuth	the angular distance of an object around or parallel to the horizon from a predefined zero point
dentelé	See ‘dancetty’ (also ‘serrated’).
corona	the outermost layer of the solar atmosphere
handsigne	A 16th/17th Century variant spelling, now obsolete, of ensign – see ‘ensign 1)’ and ‘ensign 4)’ (also 'ancient 2)').
hellas crater	A huge impact crater on Mars
ideal gas	An ideal gas is a perfect gas
steady state theory	the theory that suggests the universe is expanding but exists in a constant, unchanging state in the large scale
chondrite	Stony meteorite containing chondrules, believed to be little altered since their formation 4.6 billion years ago.
nodus	a point which casts a shadow to indicate the time and/or date on a dial face
gironné	See ‘gyronny’.
electron flux	the rate of flow of electrons through a reference surface
equiangular ~	a term used for dial types where the hour points are placed at equal angles (15º) around a circle (or part of)
accumulated	to gather or pile together
axis	The imaginary line through the middle of a rotating object around which the object spins.
epoch	An epoch is a division of a geologic period; it is the smallest division of geologic time, lasting several million years.
vitreous solid	A vitreous solid has no specific organization of molecules
chaos	A distinctive area of broken terrain.
basalt	A common volcanic rock usually grey to black and fine-grained due to rapid cooling of lava.
anode	The electrode where electrons are lost (oxidized) in redox reactions.
yachting crown	In UK usage, a crown formed from various modern yachting sails placed upon a circle or fillet that appears on the duty ensign and burgee of the British Yachting Association and is (as far as is known) unique to them – the RYA crown – but see note below (also ‘fillet 3)' and ‘naval crown').
synodic period	The interval between points of opposition of a superior planet.
sunspot	Dark patches on the Sun's surface caused by a temporary cooler region than the surrounding areas.
aphelion	the point along a planetary orbit that is farthest from the Sun;
transition region	Low solar corona characterized by a sudden increase in temperature (from a few thousand to a few million degrees).
millibar	a measure of atmospheric pressure equal to 1/1000 of a bar
negative catalyst	A negative catalyst is another term for an inhibitor
maunder minimum	A period of low solar activity, from 1645 to 1715, in which hardly any sunspots were seen
zigzag	See ‘serrated 2)'.
weak nuclear force	A fundamental force between elementary particles that can be responsible for radioactive decay.
diffusion	Diffusion is a process that happens when a substance moves from an area of higher concentration to an area of lower concentration.
degenerate ellipse	The straight line that results when an ellipse has an eccentricity of 1.00
light travel time	The time it takes light to travel a certain distance in the universe
vert	A heraldic term for the colour green (see also ‘Appendix III’ and ‘rule of tincture’).
extinction	A dimming of the light of an object, by virtue of material lying between it and the observer, which scatters or absorbs part of that light
tectonic	Geological features that result from stresses and pressures in the crust of a planet
chaos	A field of study modeling systems in nature that can be described in Newtonian terms but whose futures are, for all practical purposes, unpredicatable; e.g., the turbulent flow of water or the beating of a human heart.
reactive element	When an element is reactive, it is easily excited
moon	May be caused by a comet or asteroid impact, or by a volcanic eruption
semi-minor axis	Half of the shortest diameter of an ellipse.
saturated	A solution in which the maximum amount of solute has been dissolved in the solvent
radian	Unit of angular measurement equal to the angle at the center of a circle subtended by an arc equal in length to the radius
barycenter	The common center of mass about which two or more bodies revolve.
admiralty warrant	See ‘warrant' and its following note.
alpha centauri	Binary star system
comet	A ball of frozen dust and rock that orbits the sun and has a tail that glows
vent	the opening in the crust through which volcanic material erupts.
radiation	Radiation is energy that comes from a source and travels through some material or through space
cross-section	The area formed by a plane cutting through an object.
caldera	A large volcanic collapse crater that may be a few km across.
ratio	See ‘proportions’.
wave	A signal which propagates through space, much like a water wave moves through water.
amplify	To increase or make bigger.
mantle	A region of intermediate density surrounding the core of Earth or any other planet.
earth	Third planet from the sun; has an atmosphere that protects life and surface temperatures that allow water to exist as a solid, liquid, and gas
marks of cadency	See ‘cadency, mark of'.
radiation belt	a ring-shaped region around a planet in which electrically charged particles (usually electrons and protons) are trapped
demi	The heraldic term used when the front or upper half of an animal, or one-half of another charge is shown on a shield, banner of arms or a flag but see note below – demy or semi.
address group	In US naval usage and in some others, the group of signal flags displayed by a vessel with a flag officer or unit commander embarked, and flown (together with a call sign hoist) when entering or leaving harbour - see ‘call sign hoist' (also ‘signal flag' and ‘signal hoist').
geosynchronous	A direct, circular, low inclination orbit about the Earth having a period of 23 hours 56 minutes 4 seconds.
handguard	In Spanish military usage and possibly some others, a metal guard fixed to the staff of a military colour so as to protect the bearer's right hand (originally in combat) – a gardamano (see also ‘colour 2)', ‘colours 2)' and ‘staff 2)').
hyperbola	A hyperbola is a conic section (the intersection of a cone with a plane) that has two mirror-image branches
chemical element	A chemical that cannot be broken down into more basic chemicals.
native element mineral	A mineral that is made up of a pure element
intercalation	The source of leap years, or the addition of an extra day or other period of time in order to reconcile the solar year with that of the calendar we use
vacuum	Empty space where no matter is present.
horizon	The horizon is an imaginary circle that delimits the sky and the Earth, or an extension of the plane of the observer (at an altitude of 0 degrees).
terminator	The line separating the illuminated and dark areas of a planetary body; the dividing line between day and night as observed from a distance.
emission nebula	A glowing cloud of hot interstellar gas which is energized by imbedded hot stars.
carbonate mineral	A mineral that is made up of compounds with a carbonate group bonded to a metal
red dwarf star	The smallest and dimmest stars
hydrologic cycle	The Hydrologic Cycle (also known as the water cycle) is the journey water takes as it circulates from the Earth to the sky and back again.
x-rays	Electromagnetic radiation to the far blue end of the spectrum, with wavelengths of about 0.01-10nm, and energies of 0.1-100 keV.
quasar	Quasi-stellar object observed mainly in radio waves
deliquescence	Deliquescence describes the characteristic of some solids to absorb water and eventually dissolve
loof lirpa	Scandinavian prankster, primarily famous for his eponymous birthday (April 1, 1040).
star cluster	A large grouping of stars, from a few dozen to a few hundred thousand, that are bound together by their mutual gravitational attraction.
local time	See LT.
millibar	A measure of atmospheric pressure equal to 1/1000 of a bar
pulsar	A rotating neutron star that emits a beam of radiation, like a lighthouse beacon
contact metamorphism	Metamorphic rocks that have been formed in areas where volcanic activity has occurred
joinant	See ‘conjoined’.
upright triangle	See ‘triangle’.
adaptation	The structure, process, or behavior that helps an organism survive and pass its genes on to the next generation.
mhs	Microwave Humidity Sounder
kev	one thousand electron volts.
caldera	A type of volcanic crater that is extremely large, usually formed by the collapse of a volcanic cone or by a violent volcanic explosion
escape temperature	The temperature that particles in a planet's atmosphere will escape into space.
empirical	Derived from observation or experiment.
color	Color is a measure of reflected wavelengths of light
radiation zone	The inner region of the solar interior.
continental drift	The movement and formation of continents over long periods of time due to plate tectonics.
xml	Extensible Markup Language
mesopause	The boundary between the top of the mesosphere and the bottom of the thermosphere
sublimation	The process of a solid returning directly to a gas without changing to a liquid first.
convex	Curving outwards
ante meridiem	before noon.
kg	Kilogram
gardant	See ‘guardant’ in ‘Appendix V’.
snr	Signal-to-Noise Ratio.
proportion	An equality between two ratios.
cosmic string	a tubelike configuration of energy that is believed to have existed in the early universe
ecliptic co-ordinates	Equatorial Co-ordinates, Galactic Co-ordinates, and Horizon Co-ordinates.
interstellar dust	Small particles of solid matter, similar to smoke, in the space between stars.
amplify	To increase or exaggerate
universe	Everything which is known or thought to exist in space.
new	a phase of the Moon or other planetary object when it is unlit as seen by the observer; occurs when the object is at inferior conjunction
circumstellar disk	A torus or ring-shaped accumulation of gas, dust, or other debris in orbit around a star in different phases of its life cycle.
wind	NASA satellite for observing the solar wind, located near the Lagrange L1 point
oxidation-reduction-reaction	A reaction involving the transfer of electrons.
lunar module	the section of the Apollo spacecraft designed to land on the Moon
payload	The cargo (scientific instruments, satellites, spacecraft, etc.) carried by a rocket.
solar flare	a storm or eruption of hot gases on the sun
virtual pair	A particle and antiparticle that exist for such a brief interval that they cannot be observed.
meteorite	A rocky or metallic interplanetary object large enough to reach Earth's surface.
cartwheel galaxy	A ring-shaped galaxy in the constellation of Sculptor, at a distance of 500 million light years away
crater	A bowl-shaped hole on the surface of a planet.
sprite	Red flash linking the low atmosphere and the ionosphere of the Earth.
binary compound	A binary compound is a compound that only has two atoms
planetary nebula	A bright cloud of dust and gas around an evolved star.
cantonal triangle	The newly introduced term for a right-angled, triangular panel set with its legs (or catheti) along the hoist and upper edge of a flag as illustrated below – but see ‘triangular panel 1)’.
cmd	DSN Command System
solar prominence	A loop of plasma extending from the Sun, following a magnetic field line.
mass	The measure of a body's inertia, or how difficult it is to change its motion.
cross ~	(or cruciform ~ or crucifix ~) a dial in the form of a cross, usually of stone, with the "front" surface of the cross parallel to the equatorial plane, and the top pointing south
asteroid	Millibar A measure of atmospheric pressure equal to 1/1000 of a bar
narrow pennant	See ‘masthead pendant’.
gravity	The mutual force of attraction between two massive objects.
erb	Earth Radiation Budget
horizon	The line marking the apparent junction of Earth and sky
venn	A term (sometimes further divided into Venn A and Venn B) employed for the detailed classification of 17th Century English military colours, with particular regard to their use within a regiment (see also ‘colour 2)’, ‘colours 2)', ‘device 2)', ‘company colours' and ‘stand of colours1)').
isotope	Isotopes are atoms of the same element that have different atomic masses
interstellar absorption lines	Absorption lines in the spectrum of a distant object caused by interstellar gases lying between us and that object
galaxy	that emits more
group	On the periodic table, the columns are called groups
bacteria	Tiny living things, too small to see with the human eye
amesd	African Monitoring of the Environment for Sustainable Development
equant ~	(pron
pan-african colours	The green, yellow and red of the Ethiopian flag, adopted by a number of newly independent countries in Africa from 1956 onwards – and sometimes called the Rastafarian or Rasta colours - but see ‘Garvey colours’ and ‘Rastafarian colours’ (also (see also ‘core flag’, ‘difference’, 'flag family', ‘pan-Arab colours’ below and ‘pan-Slavic colours’).
heliocentric	Sun-centered.
language flags	See ‘linguistic flags’.
arcsecond	The second division of a degree of arc
rocket	A vehicle that burns fuel and shoots the flaming gases out one end (the engine) to move in the opposite direction
tectonic	the deformation forces acting on a planet's crust.
radiative zone	Internal region of the Sun, between the nuclear oven and the convection zone
vessel flag	In US army usage, now increasingly obsolete, a term for the special flag or pennant of an army unit, or of a type of command, flown by that unit or commander only when operating aboard a vessel – but see ‘boat flag 2)’ and note below.
conjugate base	A substance which can gain a H+ ion to form an acid.
erosion	Removal of rock and soil by any natural process.
solar	masses, and the luminous diameter of the Galaxy is some 80,000 light-years across
arc	An arc is a segment along the circumference of a circle.
steradian	(pron
crystal habit	The general form a crystal takes
catalyst	Substance that speeds up a chemical process without actually changing the products of reaction.
spectrum	electromagnetic radiation arranged in order of wavelength
radiation pressure	The force exerted on an object by light particles (photons).
pll	Phase-lock-loop circuitry in telecommunications technology.
electron volt	Abbreviated eV
ice cap	See Polar Cap
biosphere	The layer of soil, water, and air surrounding the Earth in which living organisms thrive.
fd	Fast Delivery
dissociation	Breaking down of a compound into its components to form ions from an ionic substance.
evolved star	A star that is near the end of its life cycle where most of its fuel has been used up
crystal fracture	Crystals fracture in the same way anything would fracture
meteorwrong	A jocular reference to an object thought to be a meteorite, which is not a meteorite.
aurora australis	Also known as the southern lights, this is an atmospheric phenomenon that displays a diffuse glow in the sky in the southern hemisphere
nova	a star that flares up to several times its original brightness for some time before returning to its original state.
hubble deep field	A picture taken by the Hubble Space Telescope, of hundreds of very faint, far-off galaxies in a small patch of sky.
mm	millimeter (10 m).
mascon	Concentrations of mass on the lunar surface (from mass concentrations).
qualitative	Qualitative descriptions are those that describe qualities and characteristics
ytterbium	Symbol:"Yb" Atomic Number:"70" Atomic Mass: 173.04amu
transition element	Transition elements (also known as transition metals) are found in the middle section of the periodic table
diametral ~	one of the equatorial projection dials, first described by Samuel Foster of Gresham College in the 17th century, it is a horizontal dial with a moveable style and hour points which lie along a straight line lying E-W.
betelgeuse	A star - Alpha Orionis
hemisphere	A hemisphere is half of a sphere.
nm	Nautical Mile, equal to the distance spanned by one minute of arc in latitude, 1.852 km.
earth	, and the planets are satellites of the
opposition	Configuration in which one celestial body is opposite another in the sky
precambrian	a geological term denoting the time in Earth history prior to 570 million years ago.
wane	to decrease in size
dwd	Deutscher Wetterdienst
government service jack	Generally, but not exclusively, limited to the UK and former British colonies, and flown at the bow by civilian-manned Government vessels – but see ‘colonial jack 1)’ with its following note (also ‘government ensign’ under ‘ensign’ and the notes below).
light curve	A graph showing the changing brightness of an astronomical object (usually, a variable star), plotted against time.
diurnal	daily, or occupying one day
gravity	A force of attraction, between two objects, that is proportional to the product of their masses and inversely proportional to the square of the distance between them.
vallis	a sinuous valley.
chondrule	A small (typically milllimeter-sized) glassy inclusion found in stony meteorites called chondrites
platinum	Symbol:"Pt" Atomic Number:"78" Atomic Mass: 195.08amu
cursor	a part of a mathematical instrument which slides backwards and forwards over a scale.
elastic	Elastic describes a property of rebound
ions	atoms or molecules with a differing number of electrons compared to nuclear protons, creating a charged particle
jack staff	The short staff in the bows of a ship upon which the ‘jack’ is hoisted (see also ‘ensign staff’, ‘jack’ and ‘staff 1)’).
eccentricity	A value between zero and one which represents the shape of an ellipse or an orbit
plate tectonics	Motions of a planet's lithosphere, causing fracturing of the surface into plates
sedimentary rock	A rock type that has been created by the deposit and compression of sediment
neutron	Deuterium is very abundant in Earth's oceans in a ratio of 1 : 6500 to ordinary hydrogen.
convection	One of three modes of transmission of heat (energy) from hot regions to cold regions; involves motions of masses of material.
larmes	See ‘gouttes’.
photosphere	The layer of a star from which most of its energy is released as visible or infrared radiation, this is the layer we see.
diode	An electronic, semiconductor device that allows current flow in only one direction.
magnesium	Symbol:"Mg" Atomic Number:"12" Atomic Mass: 24.31amu
meteor	A streak of light in the sky, usually lasting a few seconds at most, caused by the rapid passage of a small piece of interplanetary debris through our upper atmosphere
neutron	An elementary particle found in atomic nuclei
concentration	Concentration is the amount of one substance in a system relative to the amount of other substances
lava	Molten rock that erupts to Earth's surface through a volcano or a fissure.
gin pennant	In British RN and some other usage, an unofficial pennant of varying design – now often a defaced version of the starboard pennant in the NATO signalling code – raised when a ship’s officers wish to entertain the officers of another ship or ships (see also ‘pennant 2)’ and ‘senior officer afloat pennant’).
expanding universe	A term popularized by Eddington to describe the mutual recession of galaxies.
pallia	Pre-heraldic banners of varying design presented by the Pope to indicate his approval and/or support for a person or cause (see also ‘Bayeux tapestry', ‘gonfanon’, ‘pall’ and and ‘pre-heraldic’).
nist	National Institute of Standards.
prismatic habit	A shape of a large group of crystals that is very geometric and orderly
neutral	An object that does not have a positive or negative charge.
triptych	(pron
apastron	The apastron is the point of greatest separation of two stars, as in a binary star system orbit.
stony iron	A meteorite that contains regions resembling both a stone meteorite and an iron meteorite.
length scale	what
regio pl. regiones	A large area marked by reflectivity or color distinctions from adjacent areas; a broad geographic region.
gold	Symbol:"Au" Atomic Number:"79" Atomic Mass: 196.97amu
mineral	Inorganic compounds usually found in crystalline form
trillion	1 trillion = 1 000 000 000 000.
bandera de ceremonia	See ‘indoor flag’.
electron	A particle with a negative charge and a tiny mass
azimuth	the angular distance of an object around or parallel to the horizon from a predefined zero point.
frequency	Number of electromagnetic oscillations per second corresponding to electromagnetic radiation of any given wavelength.
kaiserliche kriegsflagge	An Imperial War Ensign – but see ‘war flag 1)' and ‘war flag 2)'.
lava	molten rock that is erupted onto the surface of a planet and is hot enough to flow.
arc degree	a unit of angular measure in which there are 360 arc degrees in a full circle.
upright centred cross	See ‘cross 1)’.
transparent	Allowing light to pass through
cms	Centre de Météorologie Spatiale (France)
ecliptic	An imaginary line in the sky traced by the Sun as it moves in its yearly path through the sky.
hypothesis	A proposed explanation of an observed phenomenon or a proposal that a certain observable phenomenon occurs.
epoch	The date used as a reference in quoting the position of stars, planets, etc, in tables
local apparent time	[L.A.T
cassini's division	The most prominent gap in Saturn's rings.
mercator projection	the most common projection used to produce a 2-D map of the globe
deuteron	nucleus of deuterium atom
speed of light	Designated as c, the speed of light is about 300,000 km/s and is constant as perceived by all observers.
large ringed feature	Unusual ringed features on the lunar surface that cannot be classified under another descriptor.
fesslet	A heraldically derived term intended to mean a single, narrow horizontal stripe – but see ‘bar’, ‘barrulet' and ‘filet' (also ‘fess').
jagiellonian cross	See ‘cross of Lorraine’ (also ‘jagiellonian’ above).
double star	a grouping of two stars
tassels	A decoration of twisted fabric or metal, often surrounding a wooden core and hanging from a cord, attached to a staff or directly onto a flag – especially a colour or parade flag (see also ‘colour 2)’, ‘cord(s) 1)’, ‘lanyard 1)’ and ‘parade flag 2)’).
bayer designation	the Greek and Latin letters assigned to stars in a constellation by Johann Bayer in 1603
mph	Main Product Header, the main description record at the start of every product, it follows a generic format.
active and inactive	In vexillology a term that may be used to describe when the rays of a star or sun emblem are shown with alternating wavy and straight rays – but see ‘sun-in-splendour' (also ‘active' above, ‘inactive', ‘rays 1)', ‘star' and its following note, ‘sunburst', ‘sun emblem' and ‘wavy').
reclination	a term sometimes used for the angle by which a reclining dial leans away from the observer (i.e
upright pile	See ‘pile 1)’.
in fess	The heraldic term used when an object, charge or charges on a shield, a banner of arms or any quartering thereof appear in a horizontal position – fesswise (see also ‘banner of arms', ‘fess’, ‘per fess’ and ‘quartering 1)’).
obelisk	a tall tapering shaft of stone, usually monolithic with a square or rectangular section ending with a pyramidal apex
force	In physics, a specific phenomenon producing acceleration of mass
radial velocity	the movement of an object either towards or away from a stationary observer.
panel	The area of a flag that is surrounded by a border, the panel itself is generally (but not exclusively) used to display charges or other designs (see also ’border’, ‘charge’ and ‘pierced 1)’).
handled	A term sometimes used to describe the hilt and pommel of a sword or dagger and the haft of a hammer, axe or other tool – but see ‘hafted’ and ‘hilted’ (also ‘shafted’).
absorption line	A narrow dark line within a spectrum
troposphere	the lower regions of a planetary atmosphere where convection keeps the gas mixed and maintains a steady increase of temperature with depth
elliptical	In the shape of an ellipse
y shape	See ‘pall’.
inclining ~	usually applied to portable dials in which a horizontal dial, designed for a high latitude, typically 60º , may be inclined by raising its southern edge (in the N hemisphere) so that it may be used at locations with lower latitudes
hydrophobic interactions	Interactions between molecules in which nonpolar portions of the molecule tend to avoid interaction with polar water molecules
fluorine	Symbol:"F" Atomic Number:"9" Atomic Mass: 19.00amu
meteorite	A meteor that has survived its passage through the atmosphere and strikes ground.
time zone	see standard time zone.
fesswise	See ‘in fess’.
greenhouse effect	An effect that causes the temperature of a planet to rise, due to the absorption of infrared radiation by gases in the atmosphere
milky way galaxy	Our home galaxy
volcano	An opening in the Earth's crust where molten lava, gases and ash are ejected.
sulphur dioxide	A colourless gas, with a strong odour, produced by burning sulphur
circumpolar star	A star that never sets but always stays above the horizon
closed universe	A universe which has a finite size and lifetime and in which space is positively curved e.g
w	West.
refractive index	A measure of how much that light is bent by a material.
silicate	a rock or mineral whose structure is dominated by bonds of silicon and oxygen atoms (ie
adeos	ADvanced Earth Observing Satellite
polar ~	a ~ in which the dial plate is set along the E-W direction and reclines so that it is parallel to the polar axis
scientific method	The method of learning about nature from making observations, formulating hypotheses, and constructing observational or experimental tests to see if the hypotheses are accurate.
light year	the distance light travels in a vacuum in a period of 1 Julian year; a unit of distance equal to about 5.9 trillion miles (9.5 trillion kilometers)
mensa pl. mensae	A flat-topped prominence with cliff-like edges.
modern ~	the equal hours as used in modern time systems
chromatic aberration	an optical lens defect causing color fringes, because the lens material brings different colors of light to focus at different points.
horsehead nebula	The Horsehead Nebula is a huge cloud of dust in space that is shaped like a horse's head
speed of light	The fastest known speed possible at 299,792.458 kilometres per second.
shine	To give off light
hz	Hertz, cycles per second.
blackbody radiation	The thermal radiation given out by a black body
astrochemistry	The branch of science that explores the chemical interactions between dust and gas interspersed between the stars.
astrology	a belief system which claims that the positions of celestial objects affect or control life on Earth
tholus pl. tholi	Small domical mountain or hill.
quartered	1) In strict (English) heraldic usage the term for where a shield or banner of arms is divided into four or more quarters but which are taken from two or more previously unconnected sets of arms is in, for example, the royal standard of England 1340 – 1605 or France and England quartered - but compare with ‘quarter the arms' (see also ‘banner of arms', ‘quarter', ‘quartering', ‘quarterly' and ‘shield 1)') 2) See ‘quarterly'.
stellar luminosity	the intrinsic brightness of a star relative to the Sun; for example, a star with a stellar luminosity of 25*L(sol) is 25 times brighter than the Sun
variable stars	Stars which fluctuate in brightness.
jehovah sun	The term – and a direct translation of the German Jehovasonne – which may be used to describe a sun in splendour, surmounted by a cartouche bearing the name of God in Hebrew lettering - a charge sometimes to be seen on (exclusively Protestant) German military flags of the 16th and 17th Centuries (see also ‘cartouche’, ‘sun-in-splendour’ and ‘surmounted by’).
density	Mass per unit volume of a substance.
matter	Anything that has mass
intelligence	The capability for abstract thought, coupled with a mastery of tools or technology
angular diameter	The apparent size of an astronomical object, against the background of the sky, expressed in angular units (degrees, minutes or seconds of arc)
synthesis	When you take two elements or compounds and combine them to create a new compound.
evolutionary track	An Evolutionary Track is the change in location of a star on the Hertzsprung - Russell (H-R) Diagram
albedo	The reflectivity of a non-luminous body, expressed as a decimal fraction
equator	The line that divides the northern and southern hemispheres.
ephemeral	Changing
polonium	Symbol:"Po" Atomic Number:"84" Atomic Mass: (209)amu
infrared space observatory	A space telescope designed to observe in the infrared region of the spectrum
rate of diffusion	This rate measurement is the speed at which molecules or atoms diffuse through a substance.
planisphere	a map of part of the celestial sphere, formed by a stereographic projection of the sphere onto a flat plane and showing (or adjustable for) the positions of the stars at a particular time and location.
meteorite	Fragment of a meteor found on the ground.
maria	Low areas on the Moon that appear dark and smooth
background radiation	Weak microwave radiation coming from space in all directions
noaa	National Oceanic and Atmospheric Administration
glas	Geoscience Laser Altimeter System
polaris	actually α Ursae Minoris, it is the star which appears quite close to the N celestial pole and is frequently used for finding north by navigators
ucar	University Corporation for Atmospheric Research
polysaccharide	These are very complicated carbohydrates made of simple sugars (glucose, fructose) in long chains
positron	Antiparticle to the electron, with a positive charge.
interstellar obscuration	Absorption of starlight by interstellar dust, causing distant objects to appear fainter.
equilibrium expressions	The expression giving the ratio between the products and reactants
omps	Ozone Mapping and Profiler Suite
basalt	a general term for dark-colored, igneous rocks composed of minerals that are relatively rich in iron and magnesium.
old	a planetary surface that has been modified little since its formation typically featuring large numbers of impact craters; (compare to young).
facula pl. faculae	Bright spot.
aurora australis	The auroral displays visible in the southern hemisphere.
polar cap	A bright layer of ice around the poles of a planetary body, which varies in size during the year.
smi	Soil Moisture Index
union pendant	See ‘budgee pendant’.
ellipse	A flattened circle, or oval.
pst	Pacific Standard Time.
volume	amount of space an object occupies.
ephemeris	A table of data arranged by date
umbra	dark central zone created by an eclipse.
vernier	a small moveable scale for obtaining fractional parts of the subdivisions of a fixed scale
albedo	The fraction of light reflected from a non-luminous body, such as a planet.
eclipse	The hiding or blocking of one celestial object by another.
individual flag.	In U.S
earth	receives 12 hours of daylight and 12 hours of darkness.
great circle	a circle on the surface of a sphere whose diameter is equal to the diameter of that sphere
x-rays	..) into an image.
lava	Volcanic rock extruded by the eruption of molten material
galaxy	A group of stars, dust and gas held together by gravity
space station	An orbiting space laboratory on which people could live and work for several years or more.
inhomogeneous	Variable in density and not the same at all locations.
tectonics	The process that forms planetary features such as continents, mountains, and faults by motion of sections (plates) of the Earth's crust driven by convection currents in the Earth's mantle.
solvent	Liquid in which something is dissolved, for example, the water in saltwater.
zamg	Central Institute for Meteorology and Geodynamics
argument of perihelion	An angle used, in combination with other orbital elements, to specify the orientation of an orbit in space
lamb of god	See ‘agnus dei’.
minor planet	another name used to describe a large asteroid.
rotational axis	An imaginary line, through the centre of a body, about which it rotates.
‘e’ cross	See ‘two-and-a-half armed cross’.
vertical triband	See ‘triband 1)’ and ‘triband 2)’.
mesosphere	Region of the atmosphere situated at an altitude of approximately 50 to 80 kilometers.
rotate	to turn around a center point, or axis, like a wheel turns on a bicycle
wanderfahne	See ‘touring flag’).
tatzenkreuz	See ‘cross pattée’ in ‘appendix VIII’
eclipse	The blockage of sunlight caused by an object passing between the Sun and another object
meteorite	A meteoroid that survives falling through the Earth’s atmosphere and colliding with the Earth’ surface is known as a meteorite.
arcus	Term for an arc-shaped feature on a planetary surface (pl
horizon co-ordinates	The system of celestial co-ordinates in which the observer's horizon is the reference plane and the north point is the reference direction
optics	The manipulation of light by reflection or refraction, usually to make an image.
mpp	Milestone Payment Plan.
diurnal	Having a daily cycle, or recurring every day.
afterglow	1
proton-proton chain	A series of thermonuclear reactions that convert hydrogen nuclei to helium nuclei, converting a tiny amount of mass into energy.
parallax	The tiny periodic shift of the apparent positions of nearby stars due to the changing position of the Earth as it orbits the Sun
decimal	The number of digits to the right of the decimal point in a number.
precision	A measure of how finely a quantity can be specified, in terms of the number of significant figures in the measurement
cantoned cross	See ‘cross cantonée’ in ‘appendix VIII’.
ellipse	A closed plane curve generated in such a way that the sums of its distances from the two fixed points (the foci) is constant.
foot	The place where a vertical circle crosses the horizon
heat capacity	A measure of how much heat is needed to raise the temperature of one gram of anything one degree Celsius.
d'alembert force	A fictitious force which appears to arises when moving along a straight line, in an accelerated manner
disulfide bond	Covalent disulfide bonds form during the tertiary structure of protein synthesis
light-year	The distance that light can travel in one year
portable ~	simply a dial meant to be moved from place to place, either as a pocket dial or simply being transportable
ftp	File Transfer Protocol
electro magnetic waves	from radio waves to gamma rays.
vallis pl. valles	Valley.
parallax	the difference in apparent direction of an object as seen from two different vantage points
troposphere	Region of the atmosphere closest to the ground, whose depth increases between the pole (8 kilometers) and the equator (17 kilometers).
iberian cross	See ‘cross of calatrava’.
mach bands	(pron
milky way	Our own spiral galaxy
cell	The smallest unit of life processes; highly organized chemical factories.
logarithmic	Increasing in powers of ten.
rocke surface	An imaginary surface in three dimensions that contains the gas in a binary star system
descendant	falling from the zenith
ephemeris second	an obsolete definition of a second used between 1955 and 1965, based on the Earth's speed of rotation
magnitude	A measurement of an object's brightness.
spectrum	the colors you see when white light is split apart
fillet	1) A frequent misspelling of the heraldic term filet - see ‘filet'
mascle	The heraldic term for a voided lozenge – see ‘voided lozenge’).
heo	Highly Elliptical Orbit
erosion	The wearing away of a surface by natural process such as lava flow, bombardment, wind, water, or other mechanisms.
declination	the angular distance north or south of the celestial equation and measured in degrees °, minutes ' and seconds "
auroral	Pertaining to aurorae.
decorated	See ‘garnished’.
respiration rate	The number of breaths a person makes per minute.
volcano	A hole in a planet's crust through which liquid rock pours onto the surface in an eruption.
abased	(adv) A heraldic term for when the main ordinary on a shield, banner of arms or flag is placed in a lower position than is usual - lowered (see also ‘banner of arms', ‘enhanced' and ‘ordinary').
palus	A Latin term meaning 'swamp' that is used to describe topographical features on the moon which resemble dark plains or swamps
ussr	The former Soviet Union.
nadir	the point directly underneath
volume	The amount of space that an object takes up.
cabled	The term for a charge, particularly an anchor, that is shown complete with its cable – but see ‘foul anchor’ (also ‘charge’).
physical property	A property that can be measured without changing the chemical composition of a substance.
nationally-cantoned flag	See ‘canton flag’.
khanda	A blue emblem, usually on a triangular pennant with saffron field and symbolic of the Sikh religion (see also ‘pennant 2’ and ‘religious flag’).
mean solar time	Time based on an average of the variations caused by Earth's non-circular orbit
deoxyribonucleic acid	Abbreviated as DNA, this long molecule in the shape of a double helix is the keyto life
apastron	the point of greatest separation of two stars, such as in a binary star system.
thermal radiation	Electromagnetic radiation emitted by a body and associated with an object's temperature; it grows greater and bluer in color as the temperature increases.
netcdf	Network Common Data Format
labes	Landslide.
farrum pl. farra	Pancake-like structure, or a row of such structures.
aperture	a small transparent hole in an opaque surface, designed to let a small beam of sunlight through to fall on a dial plate or alidade e.g
midnight	strictly, the time when the Sun achieves its most negative altitude (or, equivalently, when its azimuth is ±180º)
galaxy	The small uncertainty in the distance to the galactic centre prevents this system from being widely used.
rift valley	an elongated valley formed by the depression of a block of the planet's crust between two faults or groups of faults of approximately parallel strike.
gnomon	The central piece of a sundial which casts the shadow required to determine the time of day.
galaxy	that sometimes contains a massive
permafrost	Semipermanent underground ice.
rotation	the spin of a body about its axis.
hot spot	center of persistent volcanism, thought to be the surface expression of a rising hot plume in Earth's mantle.
shepherd's ~	see cylinder dial for the usual meaning
stp	Standart Temperature (0oC) and Pressure (1 atm)
radiant	The area in the sky where during a meteor shower the meteors appear to radiate from.
gravitational microlensing	The bending and amplification of light from a distant object by a closer object that passes between it and the observer.
absorption lines	Absorption Lines are dark lines superimposed over a bright continuous absorption spectrum
solar system	Our Sun and everything that orbits around it.
celestial poles	the Earth's north and south poles projected onto the sky
geologist	A scientist who studies the formation, structure, history and processes (internal and surface) that change Earth and other planetary bodies.
name pennant	The term for a flag or pennant that bears the name of a ship or possibly a shipping company or an institution – an onomast.
banner of the realm	A translation of the Dutch “rijksvaandel” and proposed translation of the Norwegian term “riksbanner” - a royal banner - but see ‘coronation flags’.
aurora borealis	The Northern Lights
ngdc	National Geophysical Data Center, in the USA
potential energy	The energy an object has because of its composition or position.
apparition	Period and an object is viewable in the sky.
pageant standard	A term, now obsolete, for the Scottish heraldic standard as carried on ceremonial occasions; and there are indications that it was the middle of three sizes (see also ‘battle standard’, ‘pinsel', ‘standard 4)’, and ‘great standard’).
circumpolar	an object sufficiently close to a celestial pole so that it never sets as seen from the observer's latitude
compound	Two or more atoms joined together chemically, with covalent or ionic bonds.
molarity	A measure of the number of moles of a solute that are dissolved in a liter of solution
acid	In chemistry, a substance that may have a sour taste, makes blue litmus paper turn red, and can react with a base to make salt
rotation	the spin on a body's axis
mineral hardness	Hardness is measure of mineral properties
edl	(Atmospheric) Entry, Descent, and Landing.
open crown	See ‘coronet’.
ph	A scale from 1 - 14 that measures how acidic or basic (alkaline) a substance is.
plasma physics	study of the properties of plasma
conservation of angular momentum	A useful physical rule which states that the total angular momentum in an isolated system remains constant.
sautant	The French for “leaping”, which is also sometimes used in place of, or in addition to, the heraldic terms rampant or salient – see ‘rampant’ and ‘salient’ in ‘appendix V’ (also ‘erect’ in ‘appendix V’).
temperature	Absolute temperature measured in Celsius degrees, with the zero point at absolute zero.
average	The best estimate of a quantity based on multiple measurements, given by sum of independent values divided by number of measurements made
phenomena	Something impressive or extraordinary
vertical bicolour	See ‘bicolour 1)’ (also ‘bicolour 2)’).
nonluminous	(not emitting light or visible) material that cannot be seen in the sky
full	a phase of the Moon or other planetary object when it is completely illuminated as seen by the observer; occurs when the object is at opposition
standard star	A star with accurately known magnitude and colour that can be used to calibrate images of new objects.
boiling point	The boiling point is the temperature when a liquid begins to boil and becomes a gas or vapor
base	A substance that may have a bitter taste, feels soapy, turns litmus blue, and can react with an acid to form salt
rete	{or net or spider} (usually pron
molecule	Atoms (the smallest particles of elements) bonded together to make a different substance (a compound).
iron	Symbol:"Fe" Atomic Number:"26" Atomic Mass: 55.85amu
pyroclastic	pertaining to clastic (broken and fragmented) rock material formed by volcanic explosion or aerial expulsion from a volcanic vent.
emulsion	A light-sensitive coating on photographic plates.
earth	and a radius 11.2 times the radius of the Earth
metal	A metal is a special type of element
nanometer	A unit of length equal to 10^-9 meters.
diameter	The distance from one side of a circle or sphere to the point opposite, passing through the centre.
ecliptic	(pron
random error	Error that can be reduced when separate observations are combined
ecliptic pole	One of the poles (North and South) of the Ecliptic.
photosphere	The visible outer layer of the Sun.
crust	The outermost, solid layer of a planet, with composition distinct from the mantle and differentiated by a seismic discontinuity.
hyperion	Hyperion is one of the 18 moons of Saturn
ecv	Essential Climate Variable
states of matter	Matter comes in many forms, shapes, and sizes
poke ~	an old term for a pocket or portable dial.
non-reactive	This is the opposite of reactive
finite	With an edge, not going on forever.
gear wheel	See 'cog-wheel'.
law of partition	A situation that enables a solute to dissolve in solvents based on the solubility of those solvents
alpha	Alpha is the first letter in the Greek alphabet
ruthenium	Symbol:"Ru" Atomic Number:"44" Atomic Mass: 101.07amu
cold fusion	the apparent production of power from material at room or other cool temperatures claimed to be a fusion process
shock	unusually high pressures produced briefly by an impact
pressure	Force per unit area.
photosphere	The light-emitting surface layer of the Sun.
elliptical galaxy	A common type of galaxy that has the shape of an ellipsoid (similar to a globe compressed in one or more dimensions)
volvelle	(pron
metamorphic rock	Rock formed when igneous or sedimentary rocks are modified by heat, pressure, or chemical reactions.
dust lane	A long, wide band of dust across a galaxy
prograde	The movement of a body in an anticlockwise direction around the Sun or anticlockwise rotation on its axis as seen from above the Suns north pole
erosion	The wearing away of the surface of the Earth, or other planetary body, due to natural processes such as running water.
asthenosphere	The asthenosphere is a part of the upper mantle that exhibits plastic (flowing) properties
latin cross	See ‘appendix VIII’.
absolute zero	the temperature at which the motion of all atoms and molecules stops and no heat is given off
panicles	A term used when loosely branching clusters of flowers and/or foliage form a wreath, such as the panicles of rice on the army rank flags of Taiwan (see also ‘rank flag 1)’ and ‘wreath 1)’).
neap tide	The tide which occurs near a quarter lunar phase, causing the variance between high and low tide to be minimal.
singularity	A single point of infinite temperature and pressure
undae	Dunes.
ellipse	An ellipse looks like a flattened circle
corona pl. coronae	Ovoid-shaped feature.
hafted	The heraldic term used when the handle of a hammer or an axe/mace (or of a similar tool/weapon) is of a different tincture to its head – but see ‘hilted’ (also ‘barbed’, ‘garnished’, ‘shafted’ and ‘tincture’).
earth	. Most meteorites are classified as stony
dipleidoscope	(pron
vertical meridian	See ‘meridian’.
fire alert flag	In largely US usage, a flag with a red field and inscriptions raised in conjunction with a wildfire danger warning by the Forestry Commissions of many states (see also ‘red flag 1)’).
fictional flag	A flag that appears in a work of fiction either visual or written - which may or may not have physical existence as a flag - but which is (entirely or largely) a product of the author’s imagination (see also ‘fictitious flag’ below).
carbon dioxide	A colourless, odourless gas that doesn't burn and is formed when we breath.
direct revolution	Orbital motion in the usual direction of orbital motion
measurement	A quantitative way to present scientific evidence, in the form of a number, an error or uncertainty, and a unit that represents the type of measurement.
composition percentage	This value tells the percentage of a solution that could be a percentage of mass or percentage by volume
vastitas	widespread lowlands.
planitia	a low plain.
english system	A nondecimal system of units using pounds, inches, and seconds
culmination	The position of a heavenly body when at highest apparent altitude
circumpolar	Areas of the night sky which do not travel below the horizon over the course of a year, from a particular location on the Earth
tapered swallowtail	See ‘broad command pennant', ‘burgee 1)’, ‘burgee 2)’ and ‘burgee command pennant’.
inactive	In vexillology a term that may be used to describe when the rays of a star or sun emblem, or a radiating stripe, are straight-edged – see ‘active’ (also ‘active and inactive’, ‘radiating’, ‘rays 1)’ and ‘star’ and its following note, ‘sun emblem’ and ‘sunburst’).
resolution	The smallest separation between two objects by which a telescope can distinguish them apart.
aiguillette	Loops of ornamental braided cord with tassels, and worn from the right or left shoulder of (usually but not invariably) military uniforms to signify a special status or service – see ‘flag adjutant' (also ‘cord(s)' ‘dress knot') and ‘lanyard 1)')
magnetic pole	either of two limited regions in a magnet at which the magnet's field is most intense.
earth	should intercept the surface of a
phobos	The irregularly shaped inner moon of Mars
arachnoids	Arachnoids are round networks of fractures in Venus' crust
ejecta	Ejecta is rocks, dust, and other material thrown from a volcano, impact crater, or exploding star.
focal length	The distance from the centre of a lens or mirror to its point of focus.
anaerobe	An organism that does not depend on free oxygen for its metabolism.
supernova	Stage in the life of a massive star, manifesting itself by an explosion that makes it extremely bright for a time.
conservation law	Any statement that says that a quantity in nature does not change.
photovoltaic	Materials that convert light into electric current.
sulfate mineral	A mineral that is made up of compounds with a sulfate group bonded to a metal
wedging out	(or canting out) placing wedges between a dial plate and its mounting surface
physics	The study of the forces of nature and the laws that govern the way matter and radiation interact.
altitude	The angular height of a celestial object above the astronomical horizon.
comet	Meteorite An object, usually a chunk or metal or rock, that survives entry through the atmosphere to reach the Earth's surface. Meteors become meteorites if they reach the ground.
conjunction	A time when two or more bodies appear close together in the sky
chemical replacement	A chemical reaction where one element is replaced by another
planitia pl. planitiae	Low plain.
naissant	The heraldic term for a charge or figure emerging from the side of a shield, banner of arms or a flag, or the centre of an ordinary – nascent – but see ‘issuant’ with following note (also ‘banner of arms' and ‘ordinary’).
meteorite	Rocky or metallic material which has fallen to Earth or to another planet.
crater	A bowl-shaped hole on the surface of a planetary object
sunspot	darker and slightly cooler region on the surface of the sun, created when powerful magnetic fields stop the circulation of gases.
earth	-size stellar remnant that does not exceed 1.4
hydroponic	The growth of plants using a water solution instead of soil.
in abeyance	The term used when a flag or office is no longer in current use, but which may be re-introduced at some future date – with examples being the rank flag of Marshal of France (which office has no extant holder) and the broad pennant of a commodore first class (a rank in abeyance since 1958 – see the second note following ‘flag captain'; also ‘broad command pennant 2)’ and ‘rank flag 1)’).
galaxy	with an exceptionally bright core that emits
period	The time taken for one orbit, or the time between repeated events.
local time	Represents the time of the reader, and the local time given on this website should be no more than about 30 minutes off for most of the people in the world.
altitude	The angular elevation of an object above the horizon.
meteorite	A part of a meteoroid found on Earth.
bromine	Symbol:"Br" Atomic Number:"35" Atomic Mass: 79.90amu
saros cycle	a cycle of 18 years 11 days 8 hours (223 lunations) between repetitions of eclipses.
galley	1) Generically a ship whose motive power was principally provided by her oars (see also ‘galley ensign')
gemini telescope	The new state-of-the-art telescope in Chile which was funded in part by the National Research Council of Canada.
sulcus pl. sulci	Subparallel furrows and ridges.
upright pall	See ‘pall 1)’.
centrifugal force	The outward-tending apparent force of a body revolving around another body.
caldera	A large volcanic depression at the summit of a volcano, caused by collapse or explosion.
orthorhombic crystal	This crystal forms a prism that has three edges at ninety-degree angles.
infrared	Radiation at the reddest end of the spectrum with wavelengths of 1-1300 µm.
mons pl. montes	Mountain.
gamma rays	A very high-frequency, high-energy form of light (or electromagnetic) energy
achrome	The French for colourless – but see ‘monochrome 1)'.
impact	a collision between two planetary bodies
solute	A solute is the substance to be dissolved
achondritic meteorite	An achondritic meteorite is a stony meteorite, coarsely crystallized, with large bits of various minerals visible to the naked eye.
thermonuclear fusion	reactions.
. hence stylar	pertaining to the style or gnomon of a dial (first used 1688)
equal ~	any hour system where the length of an hour is independent of the date, and the same during daytime and night-time.
telescope	An instrument for seeing faint and distant objects more clearly
radiation	Photons have no mass or electrical charge.
colles	Small hills or knobs.
cira	Cooperative Institute for Research in the Atmosphere
waxing	getting larger
hr	High resolution
sunspot	A magnetic disturbance on the Sun's surface that is cooler than the surrounding area.
greenhouse effect	An effect that causes the temperature of a planet to rise because of gases in the atmosphere.
planitia	A low plain.
stratopause	Upper boundary of the stratosphere.
electron	An elementary particle with a negative charge of –1.602x10-19 C and a mass of 9.109x10-31 kg
goos	Global Ocean Observation System
heliacal rising	(pron
binding energy	The energy required to break up a nucleus into its protons and neutrons
federal service flag	The term used in Austria and Germany for the flag flown by agencies of the federal government - see ‘state flag 1)’ (also ‘state service flag 1)’).
nuclear fission	The splitting of a massive atom into two or more lighter atoms to release energy.
limb	The outermost edge of a planetary body or celestial object
chondrules	Chondrule Small, glassy spheres commonly found in meteorites.
true formula	This formula tells you the number of atoms in a molecule for each element
deduction	A logical method for combining ideas, observations, measurements, or numbers
hydrogen	The lightest and most common element in the universe.
carboxyl group	Carboxyl groups are chemical functional groups with one carbon, one hydrogen, and two oxygen atoms (COOH)
krypton	Symbol:"Kr" Atomic Number:"36" Atomic Mass: 83.80amu
acceleration	The rate of change of velocity with respect to time.
vair	The heraldic term for a fur (reputedly that of a squirrel), which is usually (but not invariably) shown as a series of blue inverted shield or bell-like shapes on a white or silver field (see also ‘ermine’, ‘furs’ in ‘appendix III:’ and ‘potent’).
hydrocarbon	A material that is made up of hydrogen and carbon
greenhouse effect	an increase in temperature caused when incoming solar radiation is passed but outgoing thermal radiation is blocked by the atmosphere
spectral line	a line in a spectrum due to the emission or absorption of electromagnetic radiation at a discrete wavelength
quarter-field canton	A term that may be used when the canton of a flag is of a different design or colour from its field, and which occupies exactly one-quarter of that field (see also ‘canton 2)').
basalt	Volcanic rock formed by rapidly cooling lava
energy flux	the rate of flow of energy through a reference surface
isotropic	The same in all directions
parabola	A curve that extends to infinity as its arms become parallel
www	World-Wide Web.
ev	Electron volt, a measure of the energy of subatomic particles.
ecclesiastic banner	See ‘banner 3)’.
pixel	One of the elements that makes up the array in a CCD camera.
alidade	the revolving arm of an astrolabe through which sightings of the stars are made
parallel	Two lines running side by side at an equal distance apart
haurient	See ‘appendix V’.
martlet	The heraldic term for a small bird, always seen standing and usually (although not invariably) shown with thighs but no visible legs – a merlette.
urban crown	See ‘mural crown 1)’.
ats	Applications Technology Satellite
dilute solution	A solution (liquid mixture) that has a small amount of solute dissolved
heterosphere	(from heterogenous, meaning varied) -- The region of the atmosphere where lack of vertical mixing allows lighter gases to diffuse upward, and heavier gases to diffuse downward, creating substantial differences in composition at various altitudes
tdm	Time-division multiplexing.
knatterflagge	See ‘vertically hoisted flag 1)’ and its following note.
weak nuclear force	The force of nature that converts neutrons into protons and is responsible for radioactive decay.
magnetic field	May occur individually or in groups
rima pl. rimae	Fissure.
dose equivalent	The dose equivalent is a somewhat magical dose unit that in theory makes different radiations appear to be equally effective in producing biological effects in a given organ of the body even though the radiations may not be equally effective
atmosphere	An envelope of gas surrounding an astronomical body.
density	The mass of an object divided by its volume.
dialling scales	ruler-like (or rule-like) scales designed to help in the geometrical layout of dial
bar	a unit of measure of atmospheric pressure
anorthosite	The predominant rock of the lunar highlands.
heliochronometer	a precision sundial which incorporates some means to allow it to read civil (or mean) time
evidence	Scientific evidence consists of quantitative observations or experimental results that can be confirmed by other investigators.
marching flag	See ‘parade flag 1)’.
unofficial flag	A flag that has (or had) not been formally adopted by the relevant authority, but is (or has been) exhibited by supporters or enthusiasts as representing a particular entity, institution or cause, as opposed to a design or type which is so authorized or for which there is (or has been) no authorized design – see ‘official flag 1)' (also ‘de facto 2)', ‘folk flag' and ‘institutional flags (unofficial)'.
earth	are examples of small circles.
chemical decomposition	This is the molecular action of the larger process of decomposition
hydroponics	Hydroponics is a method of growing plants in water that contains dissolved nutrients (instead of in soi).
accretion	The process by where dust and gas accumulated into larger bodies such as stars and planets.
resolution	A measure of the amount of detail visible in an image
sedimentary rock	Rock formed from sediments.
auroral oval	Zone in which ionized particles are precipitated from the magnetosphere toward the thermosphere
pallasite	a stony-iron meteorite in which nodules of olivine (a silicate mineral) are surrounded by a network of iron-nickel metal.
intramolecular forces	Forces within molecules
john glenn	In 1962 John Glenn was the first U.S
wavy flame	In English then British usage, now obsolete, the term used to describe a pile wavy as it appeared on military colours – see ‘pile(s) wavy' (also ‘flammes', ‘pile 2)', ‘stand 1)', ‘venn' and ‘wavy' ).
catadioptric	Relecting and refracting
space shuttle	a spacecraft which carries people and materials into space
telescope	an instrument used to collect large amounts of light from far away objects and increase their visibility to the naked eye
density	The amount of mass per unit volume in a region of space.
supergiant	The stage in a star's evolution where the core contracts and the star swells to about five hundreds times its original size
double star	Two stars which are close to each other in the sky
radial orientation	A term that may be used to describe the orientation of a charge, particularly (but not exclusively) that of a star - for example: the star and crescent on the national flag of Pakistan are placed on a diagonal line bisecting its green panel, whilst the star on the national flag of Turkey is orientated towards the hoist and that on the flag of Sarawak has one point along the diagonal meridian – the rotational position (see also ‘star 1)').
absolute zero	At absolute zero, a hypothetical temperature, all molecular movement stops
plasma	A high-temperature gas consisting entirely of ions, instead of neutral atoms or molecules
clock ~	simply the times shown by a clock, usually civil time
maltese cross	The heraldic term for a cross resembling four arrowheads, with straight-sided arms, eight outward facing points and generally (but not exclusively), inner points which meet at the centre – a cross of (the order of) St John of Jerusalem - but see ‘cross pattée’ in ‘appendix VIII’ (also ‘cross 2)’).
band	See ‘stripe(s)’ and ‘Appendix VI’.
ms	Multi-Spectral
albedo feature	A dark or light marking on the surface of an object that may or may not be a geological or topographical feature.
maria	The dark smooth "seas" on the surface of the Moon.
boron	fifth element in periodic table - will usefully produce alpha particles when bombarded with a proton
neutron	One of the two major particles constituting the atomic nucleus; it has zero charge and mass 1.6749×10^-27 kg.
flux	The amount of energy or particles passing through a cross-section of area per second.
iron meteorite	Sunspot Areas of the Sun's surface that are cooler than surrounding areas. The usually appear black on visible light photographs of the Sun. Sunspots are usually associated disturbances in the Sun's electromagnetic field.
earth	time, defined as local Greenwich
ccar	Colorado Center for Astrodynamics Research (USA)
rom	Read Only Memory.
irs	Indian Remote Sensing Satellite
air recognition device	See ‘fin flash' and ‘roundel 1)' (also ‘aircraft marking(s)').
aten asteroids	A group of near-Earth asteroids (NEAs), named after the first of the group to be discovered (2062 Aten) They have semi-major axes of less than 1 AU
conjunction	There are at least three definitions of conjunction
chromosomes	A long strand of the DNA double helix, with the strand wrapped around a series of protein cores.
verdigris	(pron
valence number	The valence is the number of electrons that can form compounds with other atoms
evolution	Changes caused by environmental pressures over time.
nainant	A frequent misspelling of the heraldic term "naiant" – see ‘naiant' in ‘Appendix V:'.
imperial emblem	That emblem, now increasingly (but not entirely) obsolete, which represents an emperor – see ‘imperial arms’ (also ‘imperial standard(s) 1)’, ‘mon 2)’ and ‘royal standard(s)').
µm	Micrometer (10-6 m).
absorption lines	Dark lines in the spectrum of an object, caused by the absorption of light by gases lying between us and that object
gram	A gram is metric unit of measure for mass
latitude	Circles in parallel planes to that of the equator defining north-south measurements, also called parallels.
dc	Direct current.
nodule	a semi-spherical fragment of rock embedded in a matrix with a different composition.
garnished	The heraldic term used when a charge (such as a horn, helmet or mitre etc) is decorated or ornamented with details in another tincture – but see ‘adorned 2)’ (also ‘charge 1)’, ‘barbed’, ‘hafted’, ‘hilted’, ‘shafted’ and ‘tincture’)
zodiacal light	A glow, barely visible to the eye, caused by dust particles spread along the ecliptic plane.
skylight	light which reaches the observer from the general (blue) sky
soviet	From the former Soviet Union, now Russia.
modis	MODerate resolution Imaging Spectroradiometer
badge banner	The term for a small square flag showing a person’s badge, probably against livery colours, and particularly (but not exclusively) for use at that person’s funeral – a practice now largely obsolete (see also badge in heraldry ‘bannerole’, ‘great banner’, ‘grumphion’ ‘livery banner’ and 'livery colours').
force	An entity that when applied to a mass causes it to accelerate
emphasized	See ‘garnished’.
einsteinium	Symbol:"Es" Atomic Number:"99" Atomic Mass: (252)amu
orthography	the art of drawing anything without perspective, as though viewed from infinity
galaxy	a gravitationally bound collection of millions or billions of stars, gas, and dust
galactic plane	The imaginary projection of the Milky Way’s disk on the sky
saint anthony’s cross	See ‘cross tau’ in ‘appendix VIII’.
differentiated	when a (partially) molten body has been divided into two or more fractions of dissimilar compositions
molecular geometry	Shape of a molecule, based on the relative positions of the atoms.
lambert's circles	circles of construction used when drawing sets of nested ellipses to represent analemmatic dials for different latitudes, these dials using a common scale for the (vertical) gnomon position
accretion	A process of growth in which small things become large things through collisions
gravity	The force that pulls things toward each other
normality	A measure of substance equivalents that are dissolved in a volume of solution
axis	An axis is an imaginary straight line around which an object, like a planet, turns
great circle	A circle formed on the surface of a sphere which is formed by the intersection of a plane which passes through the centre of a sphere
regional metamorphism	Metamorphic rocks that have been formed in areas where heat and pressure combined to create the rock
aflame	A term sometimes (incorrectly) used in place of the heraldic term inflamed or its alternatives – see ‘inflamed'.
dmi	Danish Meteorological Institute
metamorphic rock	This is a rock type that has been reheated and crystallized
rocket	A device propelled by ejection of matter, especially by the high velocity ejection of the gaseous combustion products produced by internal ignition of solid or liquid fuels.
banner of council	In English naval usage, now obsolete, a flag (often the Royal Standard) that was used prior to the invention of a signal code to summon a council of war aboard the flagship – but see note below (also ‘flagship’ and ‘signal flag’).
gravitational collapse	When a massive body collapses due to its own mass
thermodynamics	The study of temperature, pressure, volume, and energy flow in chemical reactions.
pall flag	That flag which is used to cover a coffin prior to interment, or the deceased person when lying in state – a burial, interment or casket flag (see also ‘flag case 2)', ‘flagfolding', ‘funeral flag’ and ‘mourning flag’).
revolution	The orbital motion of a planet around the Sun or a moon around a planet.
planum	A high plain or plateau.
cellulose	A polysaccharide (carbohydrate) found in plants
caldera	A large volcanic collapse crater that can reach several km in diameter.
heisenberg uncertainty principle	This principle states that it is not possible to know a particle's location and momentum precisely at any time.
antimatter	matter consisting of particles with charges opposite that of ordinary matter
paleozoic	a geological term denoting the time in Earth history between 570 and 245 million years ago.
hydrolysis reaction	A reaction that occurs when water is added to a compound
visual binary	A binary in which both components can be seen.
chasma	Another name used to describe a canyon.
tessera pl. tesserae	Tile-like, polygonal terrain.
hypergalaxy	a system consisting of a spiral galaxy surrounded by several dwarf white galaxies, often ellipticals
cosmic microwave background	In 1992, COBE detected for the first time minute variations of temperature (the anisotropies) in the cosmic microwave background.
airglow	A faint glow of the night sky, present even in "perfectly dark" areas, caused by the recombination of particles in the upper atmosphere.
asterism	a prominent pattern or group of stars, typically having a popular name but smaller than (and not officially recognized as) a constellation; an example of an asterism is the Pleiades (M45) in Taurus
hydrophilic	Something that is attracted to water
double star	A grouping of two stars
mit	Massachusetts Institute of Technology.
chromosphere	A reddish-colored layer in the solar atmosphere, just above the photosphere.
refraction ~	dials which use a clear liquid in a solid cup to compress the hour lines
double star	Two stars which are located in the same line of sight from the Earth
permafrost	Permanently frozen ground.
atmospheric extinction	The reduction of light from a celestial object as it passes through the Earth's atmosphere.
helium	The second most abundant element in the universe
light-years	Patera A shallow crater with a complex, scalloped edge.
pulsar	A type of neutron star that has regular high powered radio and/or x-ray emissions
quantum state	The quantum description of the arrangement of electrons in an atom; allowed quantum states are filled starting with those of lowest energy first.
carbon	A very common element in the universe
binary star	two stars gravitationally bound together, orbiting a common centre of mass
meteoroid	A small, solid body moving through space in orbit around the Sun.
impale by dimidiation	See ‘dimidiated’ and following note (also ‘impale 1)').
ragged cross	A traditional symbol of Burgundy and later Spain, and a cross (more accurately saltire) composed of diagonal bars with small projections – a cross raguly (See also ‘raguly' and ‘saltire').
ferrule	A metal tip placed on the bottom of a staff (see also ‘pike’ and ‘staff 2)’).
variable star	A star whose apparent brightness will vary with respect to time.
hardness	Hardness is a measure of how easily you can scratch a substance
tm	Telemetry
metamorphic rock	Rock formed from pre-existing rocks as a result of intense heat, pressure or chemical processes.
standard conditions	Conditions used to complete formulas in chemistry
occultation	The act of one celestial body obscuring another as a result of moving between the observer and the object being observed
lanyard	1) In French military usage and in some others – and a translation of fourragère – the term for those cords and tassels that are worn on military uniforms to signify the award of a unit decoration, and may decorate that unit's military colour – see ‘cord 1)’ and ‘aiguillette' (also ‘colour 2)’, ‘cravat 1)’, ‘jack of honour’, ‘lanyard pennant’ and ‘tassels’)
equivalent	The equivalent is the mass of a compound that could replace the atomic mass of an element
inverse square law	A law describing the weakening of a force or energy flow with distance from the source as 1/R2.
inclination	The angle between the orbital plane of an object and the equatorial plane of the parent object.
radarsat	Radar satellite
safety flag	1) In Japanese usage one of several green and white flags symbolizing safe conditions in various situations (see also ‘weather flag 2)'
atlas	Atlas is one of the smallest of the 18 moons of Saturn
hamburgian coronet	A specific form of the mural crown and related directly to the city of Hamburg, Germany – see ‘mural crown 1)'
catastrophism	An early scientific school which held that most features of nature formed in sudden events, or catastrophes, instead of by slow processes.
unsaturated	An unsaturated solution has not reached the maximum amount of solute
quantum fluctuations	Microscopic violations of the law of conservation of energy, when particles can momentarily come in and out of existence
islamic prayer lines	the lines on Islamic dials where the shadow of the nodus falls at the times when Muslims must pray
nucleosynthesis	The production of all the elements on the periodic table from the fusion of lighter elements to heavier ones.
radian	[rad] the primary unit of angular measurement, it is the central angle subtended by an arc of a circle equal in length to its radius
kernelled	See ‘embattled’.
limb	the edge of the apparent disc of a celestial object
adorned	1) See ‘garnished'
subduction	the process of one lithospheric plate descending beneath another.
antipodal point	A point that is on the direct opposite side of a planet.
war ensign	See ‘naval ensign’ listed under ‘ensign’ (also ‘s').
positrons	.
diameter	the distance through a circle or sphere from one side to the other
alt azimuth	Mount type
filet	The heraldic term for a narrow horizontal stripe that is of no specified width, but which is considered to be a diminutive of bar – see ‘bar 1)’ (also ‘appendix VI’ and ‘barrulet').
double star	two stars close together in the sky; they may be a binary star system or simply the result of projection effects on the sky
electron	An electron is a very small particle that spins around the center of an atom
mercury	The small rocky planet closest to the Sun, similar in size to Earth's moon.
reflection	The change in direction of light waves or sound waves as they bounce off a surface.
light	Electromagnetic radiation in the neighborhood of 1 nanometer wavelength.
axis	also known as the poles, this is an imaginary line through the center of rotation of an object.
electron	a negatively charged elementary particle that normally resides outside (but is bound to) the nucleus of an atom.
element	A chemical material with a specified number of protons in the nucleus of each atom
meteor	A meteoroid which is in the process of entering Earth's atmosphere.
kiloparsec	a distance equal to 1000 parsecs.
free electron	Electron which is not attached to a nucleus.
sidereal	with respect to the stars
shadow sharpener	any of the various devices for sharpening the edge of a shadow, allowing more accurate time readings to be made
achromat	A lens made of two pieces of glass (or, occasionally, other materials) with differing optical properties, specifically chosen to minimize chromatic aberration.
photosphere	a thin layer in the Sun where gas changes from opaque to transparent, thus giving the appearance of a surface; the name literally means "sphere of light" and it forms the visible disk of the Sun seen in white light; the temperature in the photosphere is between 4500 and 6000 K, with an effective temperature of 5777 K
dpf	dense plasma fusion - used to denote boron and hydrogen fusion reactions especially that undertaken by Lawrenceville Plasma Physics, creating mainly alpha particles
unesco	United Nations Educational, Scientific and Cultural Organization
mev	one million electron volts.
sub-style	the line lying in the dial plane which is perpendicularly below (or behind for a vertical dial) the style
achondrite	A stone meteorite that contains no chondrules.
planet	low-mass body that orbits a star.
french revolution ~	the equal hours according to French Revolution time.
spectrograph	An instrument that separates light into its different wavelengths (or colors) and looks at the wavelength "fingerprints" to find out what substance emitted the light or what substance (gas) the light has passed through.
stereography	(hence stereographic projection) a drawing method in which a sphere is projected from a point on its surface to a plane which is tangent to it
astronomer	Someone who studies space and the objects in it
balkan cross	An often used, but incorrect, translation (balken meaning a "balk, "bar" or "beam" of wood) of the German term balkenkreuz - see ‘balkenkreuz'.
amsu	Advanced Microwave Sounding Unit
solar wind	stream of charged particles emitted from the sun.
spectrum	A transmission grating consists of a large number of narrow, closely spaced bars
mail flag	See ‘postal flag’.
hemicyclium	similar to the hemispherium, but with the south-facing part of the hemisphere cut away, and with the gnomon now projecting horizontally from the N edge.
double horizontal ~	a horizontal dial with (usually) a combined polar pointing gnomon and a vertical one showing the time/date on a stereographic projection of the sky onto the horizontal plate
cabled cross	See ‘roped cross'.
wcrp	World Climate Research Programme
planetary geology	The study of the processes and history associated with the solid, rocky objects of the solar system.
epoch	a particular fixed instant used as a reference point on a time scale for astronomical calculations, e.g
degrees	When gauging distance in degrees, hold your arm outstretched toward the sky: Image
natural	See ‘proper’.
open lozenge	See ‘voided lozenge'.
electron	will impart momentum to the electron and, since its energy has been decreased, will experience a corresponding decrease in frequency.
force	That which can change the momentum of a body
tesla	The unit of magnetic flux density i.e
occulation	the blockage of light by the intervention of another object; a planet can occult (block) the light from a distant star
exothermic	Process that gives off heat to the environment.
vehicular flag	See ‘car flag' and ‘fanion 2)'.
compound	A substance made by combining two or more parts or elements; water is a chemical compound made from hydrogen and oxygen.
'x' cross	See ‘saltire' and ‘St
oxygen	An element that is very abundant throughout the universe
navigation	directing the course of a ship or other craft
radioactive dating	A technique for determining the age of a material by measuring the amount of a radioactive isotope and its decay product.
mho	Units of conductivity that are used in the study of electricity.
liter	A liter is a metric unit of measure for volume
eccentricity	The ratio of the length between the center and the focus to the semimajor axis of an ellipse.
inertial reference frame	A reference frame in which the Law of Inertia holds (is correct)
convection zone	a layer in a star in which convection currents are the main mechanism by which energy is transported outward
diptych	literally, two leaves or pages
carbonaceous chondrite	A type of carbon-rich and volatile-rich meteorite, believed to be a nearly unaltered example of some of the earliest-formed matter in the solar system.
adaptive optics	A way of correcting for atmospheric interference using a bright reference star to measure variations and a deformable mirror to correct for them
dust	Small particles of matter
charge-coupled device	A computer chip with thousands of light-gathering pixels used in place of a photographic plate
tektite	Spherule of molten rock ejected from an impact crater and then cooled rapidly to produce glass.
gaseous planet	A planet composed of thick layers of gases surrounding a dense core.
cfc	Chlorofluorocarbon
age of globular clusters	About 12-16 billion years.
compass ~	a portable horizontal dial with an accompanying compass to allow it to be correctly oriented
astronomical unit	Distance measure
tin	Symbol:"Sn" Atomic Number:"50" Atomic Mass: 118.69amu
nova	A star that suddenly expels a huge amount of energy, experiencing a rapid increase in its luminosity which slowly fades back to its initial state.
stratosphere	the cold region of a planetary atmosphere above the convecting regions (the troposphere), usually without vertical motions but sometimes exhibiting strong horizontal jet streams.
eclipse	An event in which the shadow of one body falls on another body.
positively curved geometry	A geometry where parallel lines converge, sometimes called a spherical geometry.
hi region	Cloud of neutral hydrogen.
habited	A heraldic term used to describe the customary clothing (the "habit") of a monk or friar – habillé – but see ‘vested' (also ‘clad').
egyptian ~	a range of sundials from ancient Egypt (portable and fixed) exists, the earliest being from the time of Tuthmosis III (1479-1425 BC)
ellipse	One of a family of curves produced by rotating a circle around a diameter, and observing the resulting foreshortening
diurnal path	The path followed by a star across the sky, during one rotation of the Earth
cast	Chinese Academy of Space Technology
metamorphic rock	a rock that has been heated and compressed so that it recrystallizes, but does not melt.
frequency	the number of repetitions per unit time of the oscillations of an electromagnetic wave (or other wave)
molality	A measure of the number of moles of a solute compared to one thousand grams of the solvent
diffraction	The bending of light as it passes through a small slit or opening
rattlesnake	The image of a venomous snake (usually accompanied by the motto "don't tread on me") that is depicted either coiled or stretched - it appeared on several early American flags and may be seen on the current US naval jack – see the note following ‘union jack'.
embroider	(v) The use of needlework to create or enhance a design - employed especially on military colours and flags for indoor display (see also 'colour 2)', 'colours 2)’, ‘indoor flag’ and ‘raised detail').
electronegativity	Measure of a substance's ability to attract electrons.
evolve	To change gradually.
impact	When one body strikes another with great force
element	Something that is made up of atoms with the same number of protons in them
negatively curved geometry	A geometry in which parallel lines diverge; sometimes called a hyperbolic geometry.
adenosine triphosphate	An energy-carrying molecule, found in a cell, that contains three phosphate groups, the sugar ribose, and the base adenine.
kleestengel	See ‘cloverstem(s)’.
billion	1 billion = 1 000 000 000.
hyperbola	One of two conic sections for which there is only one closed end
afro-american flag	See ‘Garvey colours'.
albedo	surface reflectivity
palus pl. paludes	"Swamp"; small plain.
wavelength	The distance that a wave from a single oscillation of electromagnetic radiation will propagate during the time required for one oscillation.
tritium	hydrogen isotope with one proton and two neutrons in nucleus
photon	Individual particle of electromagnetic energy that makes up electromagnetic radiation.
faceted	The term which may be used to describe a charge (such as a star or sun) that is given a three-dimensional appearance by the use of contrasting colours or of simple construction lines - sectored or a star gyronny (see also ‘caltrap', ‘counterchanged’, ‘cross gyronny’ in ‘appendix VIII’, ‘sector(s) 1)’ and ‘sectored 2)’).
disaccharide	A carbohydrate that is made up of two monosaccharides.
freezing point	A temperature point when a liquid becomes a solid
chondrule	small, glassy spheres commonly found in meteorites.
aerobic	A process that requires the presence of oxygen; e.g., respiration.
universe	the space that contains all of the matter and energy in existence
mineral streak	Minerals are often ground down into a power
arcsecond	(No star is actually this close)
geomagnetic	Referring to the Earth's magnetic field.
evolved star	An evolved star is an old star that is near the end of its existence
nuclear fusion	The process in which atomic nuclei bond and create heavier elements, which releases a large amount of energy in the form of heat and light
star	A massive ball of gas which produces its own energy by means of nuclear fusion occurring within its core.
electron degenerate star	A star consisting of electron degenerate gas
red giant	A large, cool, bright star that has left the main sequence after burning all the hydrogen in its core
et-egos	Expert Team on the Evolution of the Global Observing system
flare	rapid release of energy from a localized region on the Sun in the form of electromagnetic radiation, energetic particles, and mass motions.
dodecahedral crystal	A crystal that has twelve sides
fess-point	See ‘honour point 2)’.
halbrundschild	The German term for a round-bottomed shield - see 'Spanish-style shield'.
seyfert galaxy	a main-sequence star which rotates rapidly, causing a loss of matter to an ever-expanding shell.
ptolemy's rulers	an interconnected set of three linear scales used to measure the angular positions of stars, used particularly by Regiomontanus and the Nuremberg group in the 1460s.
celestial equator	Density The amount of matter contained within a given volume
aeronomy	Field of astronomy concerning the specific study of the intermediate and high planetary atmospheres.
civil twilight	When the centre of the Sun is less than 6° below the horizon; normal daylight activities are possible.
soluble	Soluble is the ability of a substance to dissolve in another substance
tetragonal crystal	A crystal that has a basic cube shape but is stretched out
epoch	A particular period of history, or a reference point in time.
parsec	Parallax-second
masthead streamer	See ‘streamer 2)’.
geocentric	Earth-centred.
earth	and the center of the
apollo	A class of Earth-crossing asteroid.
pilot	controls and operates the shuttle
acid	Compound that gives off H+ ions in solution.
pumice	a light vesicular form of volcanic glass with a high silica content; it is usually light in color and will float on water.
garvey colors/colours	The colours introduced by Marcus Garvey in 1917 and designed to represent African-American heritage; they were internationally adopted in 1920 and are now used on several national flags – flags – the black liberation or Afro-American flag or colours - but see ‘pan-African colours’.
metric system	The system of measurement used in almost all of science
soe	Sequence of Events.
jack pin	See ‘belaying pin’.
racing flag	1) A flag flown from a yacht that is taking part in a race, and struck if it withdraws or when it crosses the finish line (see also ‘preparatory flag’, ‘prize flag’, ‘race signals’ and ‘strike’)
gravitational contraction	Slow contraction of a cloud, star, or planet due to gravity, causing heat and radiation.
albedo	The reflective property of a non-luminous object
mds	Measurement Data Set, a defined data entity within a product.
compass	A compass is a scientific instrument that tells the user the direction of magnetic north
digital information	Any form of information that comes in the form of (or can be converted into) discrete levels suitable for manipulation by a computer
constellation	an area of sky; originally a grouping of stars in the sky to form some kind of pattern; there are 88 officially recognised constellations
civil ~	the legally-accepted time scale in a particular country or region
infrared	light that is so red, humans cannot see it
cap of liberty	An ancient symbol in the form of a soft red cap which, as a consequence of having been adopted by various revolutionary movements during the 18th century, has come to be regarded as a symbol of resistance against monarchical or imperialist oppression – a liberty, Phrygian or Scythian cap.
vanadate mineral	A mineral that is made up of compounds with a vanadium oxide group or vanadium atom bonded to a metal
mole	A collection of 6.022* 1023 number of objects
debased	See ‘reversed 2)’.
designating flag	See ‘headquarters flag 2)’.
fantasy flag	See ‘fictional flag’.
unrep flag	See ‘battle flag 2)’.
degree	Angular measure, 1/360 of a circle.
particle	Small portion of matter.
centimeter	10-2 meter.
admiralty flag	1) Specifically in UK usage see ‘anchor flag' and its following note (also ‘fouled anchor')
accorné	See ‘attired'.
iron	A meteorite which is made of crystalline nickel-iron.
vertical multi-stripe	See ‘multi-stripe’.
synodic period	It is on average 29.530589 days.
heliospheric termination shock	The heliospheric termination shock is the shock that occurs as the solar wind hits the heliopause and its speed slows greatly (down to about 20 km/s).
condensate	A condensate is an example of moisture that has condensed
equation of time	The amount by which sundial time differs from mean solar time, as a result of the Earth's motion around the Sun being nonuniform during the year, and at an angle to its equatorial rotation
natural selection	The theory that states that those individuals best adapted to the ever-changing environment produce a greater number of offspring.
anomaly	In an orbit, the angle between the position of an object and the position at which it is closest to the object that it is orbiting.
celestial sphere	an imaginary sphere, arbitrarily large and co-centred with the Earth, on which all the stars appear to be fixed.
fer de moline	See ‘millrind’.
alsep	Acronym for the Apollo Lunar Surface Experiments Package
multiple ~	simply more than one dial physically incorporated into the same dial structure.
kp	Index of magnetic activity
appulse	the apparent closest approach of two celestial bodies
proton	a positively charged elementary particle
imperial war ensign	A direct translation of the German term Kaiserliche Kriegsflagge – see ‘war flag 1)' and ‘war flag 2)'.
ion	Charged atom or molecule.
sinus	"Bay"; small plain.
equator	It thus lies in the same plane as the Earth's equator
meteorite	A natural object from space that hits the surface of a planetary body
antipodal point	A point that is on the opposite side of a celestial body from a given point is an antipodal point
albedo	The albedo of an object is the amount of light it reflects
hydrogen	On Earth, hydrocarbons can be gases, liquids or low melting solids such as waxes
natant	See ‘naiant’ in appendix V.
young	when used to describe a planetary surface, "young" means that the visible features are of relatively recent origin, i.e
kilometer	1,000 meters
primum mobile	(pron
masoned	A heraldic term used to describe the lines formed by masonry blocks in a building.
diurnal motion	The apparent daily rotation of the stars (or other celestial objects) around the globe of the sky.
impact melt spherule	spherules of shock-melted rock ejected from an impact crater
imperial broad pennant	See ‘broad pennant 4)’.
halazûn dial	an Islamic dial with unequal hours, vertical gnomon and a date scale of 6 segments (each representing two signs of the zodiac).
atmospheres	Common units for measuring pressure.
ozone	Molecule consisting of three atoms of oxygen.
padded emblem	See ‘raised detail'.
refractor	A telescope whose optics consist entirely of lenses.
flexus	A very low curvilinear ridge with a scalloped pattern.
geographical ~	a dial in which the dial plate shows a map of the world, with curved hour lines allowing the time at any location to be indicated.
methane	Methane is a simple hydrocarbon with one carbon and four hydrogen atoms
quantum theory	and is one of the most important physicists of the twentieth century.
ph	pH is a measure of acidity
quarterly	A heraldic term for when the field of a shield, flag or banner of arms is divided horizontally and vertically into four quarters - but see ‘quartered 1)' (also ‘banner of arms', ‘canton 3)', ‘quarter', ‘quarter the arms', ‘quartering' and ‘shield 1)').
caboshed	See ‘appendix V’
primary body	The body that is being orbited
accretion	The building of a larger mass from smaller masses sticking together.
helium	that thus does not originate from the Big Bang
mare	A term used to describe a large, circular plain
ao	Announcement of Opportunity.
wavelength	(1) The length of the wavelike characteristic of electromagnetic radiation; (2) in any wave, the distance from one maximum to the next.
momentum	A measure of the motion of a body equal to the product of its mass and velocity.
pulsating star	See Variable Star
apsides	The plural form of apse
half moon	A term sometimes (inaccurately) used in place of crescent – see ‘crescent 1)'.
knight banneret	See ‘banneret 2)’.
refraction	the "bending" of light at the interface of two materials of different refractive indices
pseudocrater	a generally circular crater produced by a phreatic eruption resulting from emplacement of a lava flow over wet ground.
uprooted	See ‘eradicated’.
babylonian ~	number of hours elapsed since sunrise, with 24 equal hours per day
great circle	An imaginary circle on the surface of a sphere whose center is at the center of the sphere.
ultraviolet	Radiation just beyond the violet end of the visible spectrum.
filet cross	A term sometimes used to describe a plain cross with narrow arms – but see ‘filet' and ‘cross 1)' (also ‘fillet 1)' and ‘fillet 2)').
tack pin	See ‘belaying pin’.
argon	A gas that doesn't react very much.
arc-minute	Angular measure, 1/60 of a degree.
central atom	In a Lewis structure, usually the atom that is the least electronegative.
matter	a word used to describe anything that contains mass.
halide mineral	This is a mineral that is made of compounds with one or more halogen atoms
h	Hour, 60 minutes of time.
rich cluster of galaxies	Abell catalogue.
ngc	New General Catalogue
dobson units	Dobson Units (DU) are used to measure atmospheric trace gases such as ozone
heo	Highly Eccentric Orbit, see Molnya
solar cycle	The approximately 11-year quasi-periodic variation in frequency or number of solar active events.
salient	See ‘appendix V’.
ellipse	A conic section; the curve of intersection of a circular cone and a plane cutting completely through the cone.
hertzsprung-russell diagram	A diagram that shows the brightness of stars plotted against their colour or spectral type
heterosphere	Zone of the atmosphere typically situated above 80 kilometers, where each of the constituants has its own scale height since each of them has its own pressure decrease rate.
saros cycle	A period of 18 years 11.3 days in which eclipses repeat themselves.
great red spot	A very large storm, technically a high pressure anticyclone, on the planet Jupiter.
hydrogen envelope	A layer of hydrogen around a helium core in a star
11	Onboard Systems 12 -- Science Instruments 13 -- Navigation
jaipur	(pron
arctic circle	parallel of latitude at 66° 34' N
amino acid	A complex organic molecule important in composing protein and called a "building block of life".
stone meteorite	A meteorite that resembles a terrestrial rock and is composed of similar materials.
electromagnetic radiation	For amateur photography, CCDs are light-sensitive arrays that can record the amount of light coming in
heliocentric universe	A Sun-centred or Copernican Universe
dcp	Data Collection Platform
mohs scale	This is a scale that measures the hardness of rocks and minerals
dsr	Data Set Record
clementine	A space probe built by the US Naval Research Laboratory to track missiles
gps	Global Positioning System
occultation	An alignment of two bodies with the observer such that the nearer body prevents the light from the further body from reaching the observer
zero curvature	The curvature of a surface or space in which parallel lines remain parallel and the sum of the angles of a triangle is exactly 180 degrees.
wavelength	Light energy travels in waves, or pulses
nuclear reaction	A reaction that involves a change to one or more nuclei, such as nuclear fusion or radioactive decay.
seasonal ~	a form of unequal hours, usually with 12 daytime and 12 night-time hours
rastafarian/rasta colours	Symbolic of the Rastafarian movement, and (like the pan-African colours and identical to them) based upon the flag of Ethiopia – see ‘pan-African colours’.
ionization	The process of knocking one or more electrons off a neutral atom or molecule.
inflation	A very short period of huge expansion in the early stages of the Universe after the Big Bang
dynamical perturbations	Changes in the light of a star caused by its movement due to one or more orbiting planetary bodies.
naval jack	Flown at the bow of a warship, often the appropriate national flag (or a variation of it), occasionally the same as the naval ensign, or sometimes a completely different design - the jack (see also ‘masthead pennant 1)’, ‘naval ensign’ under ‘ensign’, ‘jack staff' and ‘suit of flags’).
elliptical	shaped like an egg, but with equal ends
convection	Transfer of thermal energy via fluid currents (gases or liquids).
astronomy	the scientific study of celestial objects
occultation	The passage of one object in front of a smaller one, temporarily obscuring all or part of the background object from view.
vested	The heraldic term that is properly employed to describe the vestments of a bishop, archbishop or prince of the Church, but which is sometimes used for the habit of a monk or friar – but see ‘habited' (also ‘adorned 2)' and ‘clad').
rfi	Radio Frequency Interference.
density	light we receive from celestial objects is refracted, which makes us see such objects higher in the sky than they really are
orbit	the path followed by an object in space as it goes around another object; to travel around another object in a single path
deck flags	A term to describe the practice, now obsolete, of showing a display of flags along the sides of a ship as illustrated below – see ‘pavisade' and ‘streamer 2)' (also ‘ancient' and ‘postures').
evolved star	a star that is near the end of its life cycle where most of its fuel has been used up
oxidizer	An oxidizer can also be called an oxidizing agent
earth	, the
magellanic clouds	The two Irregular galaxies that accompany the Milky Way.
colligative properties	Properties of a solution that depend only on the number of particles dissolved in it, not the properties of the particles themselves
shell star	A type of star which is believed to be surrounded by a thin envelope of gas, which is often indicated by bright emission lines in its spectrum.
achondrite	a stony meteorite representing differentiated planetary material.
sharp	Standard-family HRPT Archive Request
sanguin	The heraldic term for blood-red - see ‘shades of tincture' in ‘Appendix III'.
parallels	Circles in parallel planes to that of the equator defining north-south measurements, also called lines of latitude.
lto	Linear Tape-Open
hatchment	See ‘achievement 2)’.
gravity	A force that causes all matter to be attracted to all other matter.
atmosphere	A layer of gas surrounding an object in space.
bacteria	The smallest type of living organisms.
diptych ~	(pron
armillary	(pron
pole	end of an axis, or the point where an axis meets the surface of a planet (geographic); either end of a magnet and points where the magnetic forces originate (magnetic).
one-and-a-half armed cross	The term used in Eastern European heraldry – and a direct translation of the Polish Póltora krzyz – that describes a Latin cross which has a second horizontal arm projecting on one side only - usually the sinister (see also ‘cross 2)’, ‘cross of Lorraine’, ‘Latin cross’ in ‘appendix VIII’ and ‘two-and-a-half armed cross’).
humidity	The amount of water vapour in the air.
organism	An ordered living creature.
tidal ~	a dial delineated to give the times of the marine tides
phase	The particular appearance of a body's state of illumination, such as the full phase of the moon .
culmination	An object culminates when it reaches greatest and least altitudes (upper culmination and lower culmination respectively)
hydrophilic interactions	Interactions between molecules where nonpolar portions of the molecule are attracted to any interaction with polar water molecules
planum pl. plana	Plateau or high plain.
oceanus	A very large dark area on the Moon.
regolith	A powdery soil layer on the Moon and some other bodies caused by meteorite bombardment.
radiated	(adj) A heraldic term used when rays are seen issuing from a charge for example the Madonna radiated as shown below but see ‘radiant’ (also ‘radiating’ and ‘sun-in-splendour’).
analemma	A figure-eight shaped curve, often shown on globes as a graphical representation of the Sun's north-south position on different dates (shown by dates located at various positions along the curve), and the amount by which sundial time differs from mean solar time on those dates (shown by the width of the curve at those dates).
scopulus	Lobate or irregular scarp.
mwhs	Microwave Humidity Sounder
aurora	Lights seen in the upper atmosphere
granite	A rock type of modest density and high silica content, formed in association with differentiation processes and, therefore, found primarily on the Earth.
balzaus	See ‘bauceant’.
coriolis effect	An effect which changes the apparent horizontal motions of objects moving on a rotating body
jovian	Jupiter-like or of Jupiter.
molecule	A substance made up of two or more bound atoms.
cycloid	(pron
basalt	A type of volcanic rock, often formed in lava flows, which is common on the Moon and terrestrial planets.
jcomm	Joint Commission for Oceanography and Marine Meteorology
harnysed	The heraldic term used when a human figure is clad in armour – but see ‘vambraced’ (also ‘armoured’ and ‘armed 2)’.
proton	An elementary particle found in all atomic nuclei
archimede’s principle	Principle that a body submerged in a fluid is buoyed up by a force equal in magnitude to the weight of the fluid that is displaced, and directed upward along a line through the center of gravity of the displaced fluid
nadir	The point with a negative ninety degree inclination in relation to the observer, or the point directly beneath their feet
heat of fusion	The amount of energy required to transform a substance from a liquid state to a solid state
cosmic string	A tube-like configuration of energy that is believed to have existed in the early universe
limiting reagent	The reactant that will be exhausted first.
orbital period	the amount of time it takes a spacecraft or other object to travel once around it's orbit.
einstein-rosen bridge	A Einstein-Rosen Bridge (named for Albert Einstein and Nathan Rosen, and commonly known as a wormhole in space) is a mathematical solution to Einstein's theory of General Relativity
anorthosite	Anorthosite is a type of rock found on the moon, on lunar highlands
elongation	The angle between two bodies
observable universe	The parts of the universe that can be detected by the light they emit.
heavy-metal star	A heavy-metal star is an unusual type of giant star
wedge	See ‘pile 3)’.
neutron	A particle found in the nucleus of an atom
conservation of energy	A law of nature stating that the total amount of energy in an isolated system always remains constant.
rupes	Scarp.
national pennant	See ‘wimpel 1)'.
inert	The word inert is used to describe the elements in group eight
digital ~	an ingenious 20th century dial
vambraced	The heraldic term used when an arm only is shown clad in armour - but see ‘harnysed’ (also ‘armoured’ and ‘embowed’).
prokaryote	Cell that contains a single long strand of DNA but no nucleus
atomic nuclei	An unstable nucleus may decay to one or more lighter nuclei
mass	the measure of the amount of matter in an object
absorption nebula	A type of nebula that blocks light from sources behind it
eyepiece	A system of one or more lenses used to magnify and view the image formed by a telescope.
space	The container without walls of all matter and energy.
concentration	The amount of substance in a specified space.
queen's colour	See ‘colour 2)' and ‘colours 2)'.
distilled water	Distilled water is pure water
magnitude	See Apparent magnitude, Absolute magnitude.
electron-volts ev	measure of energy based on accelerating an electron through one volt
waning	getting smaller
dioptre	(also diopter) A measure of the refractive power of a lens
magnetic pressure	Pressure exerted by magnetic forces.
sunshine recorder	a meteorological instrument for recording the hours in which the Sun shines
random process	A process in which the timing of an individual event is unpredictable, even though the rate of events may be well-determined
full moon	Lunar phase during which the entire visible surface is under illumination
noaa	National Oceanographic and Atmospheric Administration - NOAA website NOAA is an American organisation dedicated to studying the the oceans and atmosphere in the interest of predicting changes to the climate, weather and oceans.
life	A self-contained set of chemical reactions involving carbon based molecules
alpha centauri	Alpha Centauri is the star system that is closest to the Earth
ipn-isd	(Obsolete
star classification	See Spectral classification.
space curvature	The curvature of three-dimensional space; one of the consequences of general relativity
facula	A region or spot that is brighter than the rest of the solar surface.
macula pl. maculae	Dark spot; may be irregular.
dynamical ~	[or Terrestrial Dynamical Time, TDT] "scientific time" – it superseded ephemeris time in 1984, and is based on a uniform scale of time derived from atomic clocks (i.e
crescent	a phase of the Moon or other planetary object when it is less than half illuminated as seen by the observer
season	A particular time of year which has a certain type of weather
cambridge flag	See ‘continental colours’.
aurora australis	The Southern Lights
magma	Molten rock within a planet or moon.
conic section	A plane curve obtained by cutting a cone with a plane
meteoroid	A small rock in space.
planet	Apastron The point of greatest separation of two stars, such as in a binary star system.
gregorian calendar	the calendar first introduced by Pope Gregory XIII in 1582 AD and now the accepted calendar throughout the vast majority of the world
isotopes	variations in the nucleus of atoms, having the same number of protons and varying numbers of neutrons
cloisonné	a term sometimes used to describe the technique of making metal dials by deeply etching the lines and numerals and then filling them with coloured material
base	Substance which gives off hydroxide ions (OH-) in solution.
torquetum	(pron
yacht officer's flags	See ‘officer’s flags’.
radiant	a point in the sky from which meteors in a meteor shower seem to originate.
crater pl. craters	A typically bowl-shaped or saucer-shaped pit or circular depression, generally of considerable size and with steep inner slopes, formed on a surface or in the ground by the explosive release of chemical or kinetic energy; e.g., an "impact crater" or an "explosion crater".
crystalline	indicates a rock is composed of mineral crystals rather than glass
mm	millimeter (10-3 m).
newton's law of gravitation	Two bodies attract each other with a force that depends on the product of their masses divided by the square of the distance between them
fluorescence	The phenomenon of emitting light upon absorbing radiation of an invisible wavelength.
igneous rock	A rock type that has been created from super-heated magma
inflamed	The heraldic term used when a charge is shown with flames coming from it – ardent, enflamed or flamed – but see ‘incensed 1)’ (also ‘flamant').
galactic cluster	A few dozen to a few tens of thousands of stars, regularly or irregularly scattered across a few tens of light-years
idcs	International Data Collection System
inner transition elements	Elements in the periodic table that have three shells that are not filled with electrons
eyepiece	This was invented by Isaac Newton.
inhibitor	An inhibitor is a compound that slows down the process of a reaction
mare	Areas on the Moon that were originally thought to be seas filled with water but are now believed to be solidified lava.
st george’s ensign	In English later British RN usage now obsolete, the term to describe a white ensign charged with a Cross of St George overall (as per the present pattern), and formerly used in order to differentiate it from one having a plain fly (see also ‘canton of St
territorial flag	See ‘sub-national flag’.
gravity	the force that attracts objects to each other.
conjunction	1
density parameter	The ratio of the mean mass density of the local universe to the density required to just halt the universal expansion, given the symbol Omega(0).
pptl	Processor Point Target Linearity
x-rays	.) towards a camera or detector.
radioactivity	Radioactivity occurs when the nucleus of an atom breaks up into two or more pieces
us executive order	See ‘executive order’.
mdd	Meteorological Data Distribution
ip	Internet Protocol
sub-nodus	the point on the dial plane that lies perpendicularly below (or behind for a vertical dial) a nodus
liquefaction	A process that increases the pressure on a gas until it becomes a liquid
electoral cap	The term for a coronet (of varying design) now obsolete, that appeared above the arms of those German rulers who (until 1806) had the hereditary right to elect an emperor of the Holy Roman Empire, with a typical example being that above the Hanoverian inescutcheon on the royal standard of the UK from 1801 – 1816 (see also ‘coronet 2)’, ‘inescutcheon’ and ‘royal standard’.
fin flash	A term for the national colours (or sometimes the national flag/an emblem therefrom) when painted as a symbol of nationality on the tail plane/fin of largely (but not exclusively) military aircraft - a fin marking or rudder stripes (see also ‘fuselage marking(s)’, ‘aircraft marking(s)’, ‘flag emblem', ‘roundel 1)’, ‘national colours 2)’, and ‘wing marking(s)’).
regolith	A residual mixture of fine dust and rocky debris, usually produced by meteor impacts, covering the lunar surface.
fermi paradox	The contradiction between the high estimates for the number of advanced civilizations in our Milky Way galaxy and the fact we don't have any evidence regarding their existence
az	Azimuth.
latin cross throughout	See ‘appendix VIII’, and ‘off-centred cross 2)’ with its following note.
retrograde	The movement of a body in a clockwise direction around the Sun or clockwise rotation on its axis as seen from above the Suns north pole
fusion	The process in which two atoms join together to make a different atom, usually releasing a huge amount of energy in the process
canton of st. george	The term used when a flag’s canton is formed by the red cross of St George on its white field – a St George’s canton (see also ‘canton 2)’, ‘canton flag’, ‘St George’s Cross 2)’ and ‘St
oxygen	ozone (O3), helps protect the biosphere from ultraviolet radiation with the high-altitude ozone layer
mass	A measure of the amount of material of an object.
ahaz	supposed refraction dial, from the Bible story (Kings 20 v8-11) which may allude to a dial showing time running backwards.
radius	The straight line from the centre of a sphere or circle to any point on its surface.
sphere	Anything in the shape of a ball
covalent bond	A chemical bond where electrons are shared between two atoms
penumbra	the area of partial illumination surrounding the darkest part of a shadow caused by an eclipse.
toroidal radius	in a solar loop structure, it is the distance from the axis of the loop to the center of the "semi-circle" that the loop forms
lava	Molten rock that issues from volcanoes
cosmic ray	A very fast moving atomic or subatomic particle travelling through space
boyle's law	A scientist named Robert Boyle came up with an understanding of the way pressure and volume are related (at constant temperatures)
decimal system	The system of counting and arithmetic based on factors of ten (the binary systemis based on factors of two).
earth	and an orbiting
saint andrew’s ensign	See ‘St Andrew’s cross 3)’ above.
light-year	The distance light travels in 1 year, 9.5x 101^2 km.
civil time	see Time (types of) civil~.
greenwich meridian	the line of longitude (or half a great circle) passing through the centre of the Airy transit circle at the old Royal Greenwich Observatory in London, and which defines the origin of Longitude (º = 0º)
critical temperature	The temperature that must be reached in order for a new nuclear reaction to begin within a star
radius	Half the diameter of any sphere or circle
make her number	(v) To hoist that group of signal flags which identify a ship in a recognized code code – a term now increasingly obsolete – see ‘call sign hoist’ and the note below (also ‘International Code of Signal Flags’, ‘pendant number’, ‘private signal 3)’ and ‘signal flag’).
ghrsst	Group for High Resolution Sea Surface Temperature
dvb-s	Digital Video Broadcast by Satellite
coordinate system	A system used to identify locations on a graph or grid
space astronomy	Astronomy that uses the unique advantages of the space environment, including sensitivity to infrared and high-energy electromagnetic waves, and freedom from the blurring effects of the Earth's atmosphere
altitude	In the Altitude-Azimuth coordinate system, the angle vertically from the horizon in the celestial sphere.
arc-second	Angular measure, 1/3600 of a degree.
ceres	Clouds and Earth’s Radiant Energy System
polyhedron ~	a multiple dial in the form of a solid polyhedron, with a separate dial on each face
active region prominence	Streamers of solar matter that can reach an altitude of 10,000 kilometers
satellite	A body that revolves around a larger body
valence mechanism	This mechanism is the way an atom bonds to other atoms to create stable (full) electron orbitals.
ellipse	An ellipse is an oval shape
convection	the physical upwelling of hot matter, thus transporting energy from a lower, hotter region to a higher, cooler region
earth	and a radius 4.0 times the radius of the Earth
crust	The rocky surface layer of a planetary body.
gregorian calendar	Essentially the modern calendar system, introduced around A.D
waterwheel	The term for a representation of a wheel that usually (but not invariably) provides the motive power for the grinding of wheat or other cereal – a water-wheel or millwheel – see ‘millstone' (also ‘cog-wheel' and ‘windmill'.
origin	the (0,0) point (or (0,0,0) in three dimensions) of a co-ordinate system used to describe a dial plane
rhyolite	fine-grained extrusive igneous rock, commonly with phenocrysts of quartz and feldspar in a glassy groundmass.
embraced	See ‘interlaced’.
isomer	An isomer is a molecule or compound that has the same number of atoms as another but a different structure
lead	Symbol:"Pb" Atomic Number:"82" Atomic Mass: 207.20amu
indented	See ‘dancetty’ (also ‘embattled').
celestial body	an object that is located in outer space
galaxy	types that included:
day	Amount of time it takes the Earth to spin once on its axis.
coriolis force	An imaginary ('fictitious') force, which can be used to explain the Coriolis effect, if one wishes to ignore the rotation which actually causes that effect
archaea	The most ancient of the three major branches of life on the Earth; others are Eukarya and Bacteria.
epicycle	A small circular motion superimposed on a larger circular motion.
declination	The angle of an object above or below the celestial equator
king’s broad pennant	See ‘broad pennant 4)’.
mathematics	The study of numbers and their properties, and the symbols and operations that can apply to numbers.
solar day	divided by (24 x 60 x 60).
balk cross	An accurate but seldom used translation (balken meaning a "balk, "bar" or "beam" of wood) of the German term balkenkreuz - see ‘balkenkreuz'.
coronagraph	Optical instrument simulating an eclipse.
deuterium	hydrogen isotope with one proton and one neutron in nucleus
effusion	Movement of gas molecules through a small opening.
megha-tropique	A joint CNES-ISRO mission
simulation	A computer program that works out what something should do or look like without actually having to see it.
primary body	i.e
orbit	The closed path of one object around another.
ejecta	Material blown out of a crater during an impact on the surface.
iso	International Standards Organization.
osmosis	This process happens when water molecules move from an area of high concentration to low concentration
intercalation	The insertion of an extra day or month into a calendar, to make the average length of the calendar year more nearly equal to the seasonal year
constellation	groups of stars in that people have imagined to represent various objects or mythical beings
nm	An abbreviation for nanometers
relative density	When the absolute density of a gas is compared to the density of air
valence	Valence is a measure of how much an atom wants to form compounds with other elements
star	a ball of gas which radiates energy
late-gothic shield	The term sometimes used (albeit inaccurately) in vexillology to describe a round-bottomed or Spanish-style shield - but see note below (also ‘rectangular shield’, ‘shield 2)’ and ‘spanish-style shield’).
terrestrial	a term used to describe anything originating on the planet Earth.
umbra	The name given to the shadow cast by a celestial object that entirely blocks out illumination.
spectral type	The classification of a star due to its spectrum
ecliptic	moving southward.
magma	very hot, fluid rock
impact-trigger theory	The leading theory of the moon's origin, in which material was blasted off Earth's mantle and then reaccumulated to form the Moon.
electrovalence	Electrovalence is the ability of an element to bond with other elements by giving or receiving an electron
affrontant	See ‘respectant' in ‘appendix V'.
catoptric	Concerning reflections
modulation	The process of modifying a radio frequency by shifting its phase, frequency, or amplitude to carry information.
energy	Ability to do work.
amv	Atmospheric Motion Vector
chloroplasts	The main energy transformation organelles in plant cells; places where the molecules of chlorophyll are found and photosynthesis occurs.
convective zone	An area within a star where convection currents are largely responsible for energy transport.
cosmic abundance	The average abundance in the universe of all the stable elements.
albedo	An object's albedo is the ratio of the amount of solar radiation reflected from an object to the total amount it receives
cathode	Electrode where electrons are gained (reduction) in redox reactions.
stained glass ~	a (generally vertical) dial in which the dial face is of stained glass, and is viewed from the back, i.e
extraterrestrial	An adjective that means “beyond the Earth.” The phrase “extraterrestrial life” refers to possible life on other planets.
steady state theory	The theory that suggests the universe is expanding but exists in a constant, unchanging state in the large scale
hâfir dial	an Islamic dial with unequal hours, vertical gnomon and equiangular date scale of 12 segments.
methane	CH4
orbital	The orbital is where an atom keeps its electrons
balcanifer	A medieval term for the standard bearer of the Knights Templar (see also ‘bauceant’ and ‘enceniator’).
heliacal rising	The rising of a star in morning twilight just early enough to see the star before the sky is too bright to see it, or the date on which that occurs
ecliptic	moving northward.
reflect	If light is reflected by an object it bounces back from the object instead of going through it or being absorbed
debris	the remains of anything broken down or destroyed
pinch effect	collapsing or indrawing of electric fields in a plasma or similar current carrying material which can create a more intense plasma reaction
phosphate mineral	A mineral that is made up of compounds with a phosphate group bonded to a metal
spiral arm	In spiral galaxies, one of the arms lying at an angle to the Sun-center line
vastitates	Extensive plain.
quark	A fundamental particle that makes up hadrons, and has a charge of either 2/3 or -1/3
chlorophyll	Chlorophyll is the pigment in plants that absorbs light rays
galaxy	, the
compass rose	a drawing of the compass directions, showing as a bare minimum the cardinal points, but more usually eight, sixteen or thirty-two points.
horarius circle	(pron
molecular mass	Molecular mass is another term for formula mass
celestial co-ordinates	A system by which the position of a body on the celestial sphere is plotted with reference to a reference plane and a reference direction
space lab	A space lab is a laboratory where the astronauts work in space
equinox	The date when the Sun passes through the Earth's equatorial plane (occurs twice annually).
mtg	Meteosat Third Generation
glycerol	Glycerol is a biological compound that has three carbons with three alcohol functional groups
phase	Any one of several predefined periods in a mission or other activity.
lan	Local area network for inter-computer communications.
extragalactic	Extragalactic means outside of, or beyond, our galaxy (the Milky Way Galaxy).
observer	A person who looks at an object.
big bang	The most likely idea for the beginning of the Universe, in which the Universe has expanded from a single point
paschal moon	(pron
holmium	Symbol:"Ho" Atomic Number:"67" Atomic Mass: 164.93amu
atom	The smallest particle of a chemical element that can take part in a reaction
mutation	The fundamental mechanism for generating change in genetic material
systolic	the squeezing of the heart ventricles as they push blood along the arteries.
terminator	The line between day and night on any celestial object.
theory	An explanation of a natural occurrence that is testable and capable of predicting future occurrences.
cosmic nucleosynthesis	The fusion of light elements during the early hot phase of the big bang, to produce heavier elements
chemical changes	Processes or events that have altered the fundamental structure of something.
matter	A word used to describe anything that contains mass.
force	A pull or a push that causes an object to speed up or slow down in a particular direction.
g-pod	GRID - Processing On Demand
periodic table	A way of organizing the elements according to the number of outer electrons in each atom
regiomontanus ~	a universal form of card dial, usually with the suspension point of the cord movable in two dimensions in the card plane
carbon	Symbol:"C" Atomic Number:"6" Atomic Mass: 12.01amu
hardness points	Steel rods used by geologists to test the hardness of minerals and rocks.
co-latitude	equals 90° – latitude.
commensurability	A relationship between orbital periods which involves
urinant	See ‘appendix V’.
matter	Anything that has mass and takes up space
carbon dioxide	methane appears in Earth's atmosphere and is a greenhouse gas with a high global warming potential
beta particle	The electron or positron given off by beta decay.
galley ensign	In largely Mediterranean usage, a distinctive ensign or flag now obsolete, that was specifically flown from a warship whose principal motive power came from her oars rather than her sails (see also ‘ensign’ and ‘galley’).
ray	A streamer of ejecta associated with an impact crater
meteoroid	dust and debris that travel through space and become meteors when they enter Earth?s atmosphere.
zirconium	Symbol:"Zr" Atomic Number:"40" Atomic Mass: 91.22amu
salts	Ionic compounds that can be formed by replacing one or more of the hydrogen ions of an acid with another positive ion.
magnetic field	The region surrounding an object which has a changing electric field
planet	a very large body in orbit around a star
fossil	The remains of a living organism that have been turned to stone over a long period of time.
celestial poles	Two points, the North Celestial Pole, and the South Celestial Pole, which are at the ends of the imaginary axis about which the sky appears to turn.
biology	The branch of science devoted to the study of living systems.
albedo feature	a dark or light marking on the surface of an object that may or may not be a geological or topographical feature
ion	A charged particle consisting of an atom stripped of one or more of its electrons.
rupes	the term applied to scarps on planetary surfaces; many scarps are thought to be the surface expression of faults within the crust of the planetary object.
evaporation	Evaporation is a molecular phase change of a liquid to gas or vapor
solar seismology	The study of natural vibrations and oscillations in the Sun as a way to probe the structure of the solar interior.
aao	Anglo-Australian Observatory, based in New South Wales, Australia
white dwarf	the remains of an old star after it uses its energy
axion	A hypothetical elementary particle that may be a form of hot dark matter
differentiation	Any process that tends to separate different chemicals from their original mixed state and concentrate them in different regions.
arc minute	one 1/60 of a degree.
landesfarben	See 'national colours 2)' and 'state colours 3)' (also 'livery colours').
southern hemisphere	The lower half of our planet where Australia can be found.
nucleo synthesis	and are therefore the heaviest elements which do not require a supernova explosion for formation
earth	. Because the zodiacal constellations were defined 2,000 years ago,
absolute altitude	The height of any point on the Lunar surface in comparison to the "reference sphere," a perfect sphere of 3476 kilometers in diameter which represents the mean height of average terrain on the Moon.
trajectory	The path of a projectile or other moving body through space.
spectrum	Earth's atmosphere is transparent to radio waves with wavelengths from a few millimetres to about twenty meters
galaxy	or the radiated energy from the
terminator	the boundary between the illuminated and dark areas of the Moon or other planetary body
mass	A measure of the total amount of material in a body, defined either by the inertial properties of the body or by its gravitational influence on other bodies.
axis	A straight line used as a reference or about which an object can turn.
fan	A semi-circular patriotic decoration in bunting, usually (but not invariably) of flag design and/or colours - a swag (see also ‘bunting 2)’ and ‘mourning bunting').
hydrogen bond	A chemical bond that has hydrogen covalently bonded to an electronegative atom
due	Data User Element
geological time scale	The sequence of events in the history of the Earth.
distillation	Distillation is a process in which one substance is boiled away from another and then collected
gps	a system of polar-orbiting satellites, run by the US Dept
berkelium	Symbol:"Bk" Atomic Number:"97" Atomic Mass: (247)amu
meson	A sub-atomic particle of intermediate weight.
dynamo	A device, such as a turbine, used to turn motion into electromagnetic energy
millimeter	10-3 meter.
chromosphere	The lower layer of the atmosphere of the Sun.
prominence	A looping column of gas ejected from the surface of the Sun.
acidic	Describes a solution with a high concentration of H+ ions.
major axis	The maximum diameter of an ellipse.
tuff	the general term for consolidated pyroclastic debris.
astrolabe	an early astronomical instrument in the form of a heavy disk (the mater) which was suspended vertically and had an angular scale marked around it (the limb)
officer’s pennants	The term that may be used to describe those pennants (often - but not exclusively - a swallow-tailed version of the relevant club burgee or flag) flown by the past or present officers of a club, especially of a yacht or boating club – a flag officer, yacht officer or officer's broad pennant or a yacht officer's pennant – but see ‘officer's flags’ and ‘broad pennant 3)’ (also ‘burgee’ and ‘swallow-tail(ed)’).
right ascension	the longitude of a point on the celestial sphere using the equatorial coordinate system; right ascension divides the sky into 24 sections called hours (1 hour = 15 degrees)
energy	Energy is the capacity for doing work
aurora	Auroras are beautiful undulating sheets of light in the near-polar sky
ccd	Charged Couple Device
red giant	a stage in the evolution of a star when the fuel begins to exhaust and the star expands to about fifty times its normal size
scientific ~	a term usually taken to mean a dial which is designed to show equal hours, or at least in which the effect of latitude been mathematically accounted for
terra	an extensive land mass.
osmium	Symbol:"Os" Atomic Number:"76" Atomic Mass: 190.20amu
radiant	(adj) The heraldic term for rays that expand from a central point, but which may also be applied to other charges and to ordinaries that are similarly arranged – rayonné or rayonnant - but see ‘radiated’ and the note below (also ‘gyronny’, ‘ordinary’ and ‘radiating’).
astrolabe	An astrolabe is an instrument that was used to determine the altitude of objects (like the sun) in the sky
nsf	National Science Foundation.
reflecting ~	these dials have no gnomon, but reflect sunlight by means of a semi-cylindrical mirror, set with the axis of the mirror parallel to the polar axis
fy	Fiscal year.
shield volcano	a volcano in the shape of a flattened dome, broad and low, built by flows of very fluid lava.
starch	A long chain of carbohydrates formed in plants
king’s jack	See ‘His Majesty's Jack'.
earthquake	Vibration or rolling motion of the Earth's surface accompanying the fracture of underground rock.
time	A measure of the flow of events.
population ii stars	Stars found in the halo and nuclear bulge of the galaxy
carbon	nitrogen and oxygen
eukaryote	Cell with a nucleus, that is, with DNA contained by an interior membrane; a multicelled organism
ozone layer	A layer of ozone (O3) in the stratosphere of Earth's atmosphere that absorbs dangerous ultraviolet radiation from the Sun.
ray	A beam of light
meteor	mass of rock or metal that enters Earth?s atmosphere, usually burning up before reaching the planet?s surface.
mgn	The Magellan spacecraft.
semimajor axis	one-half of the longest dimension of an ellipse.
boron	Symbol:"B" Atomic Number:"5" Atomic Mass: 10.81amu
epoch	A date chosen as a reference point for observation
element	A substance that cannot be split into simpler chemical substances
curium	Symbol:"Cm" Atomic Number:"96" Atomic Mass: (247)amu
solar wind	Flow of lightweight ions and electrons (which together comprise plasma) thrown from the sun.
layered saltire	A term that may be used to describe any saltire where an arm of one colour overlays (or apparently overlays) an arm of a different colour as in the examples given below (see also ‘layered cross’, ‘saltire’ and ‘tripartite').
cavus	A hollow, irregular depression.
mixture	Mixtures are substances held together by physical, not chemical, forces
aircraft insignia	1) Specifically in US military usage, the term that refers to markings of identification on the tail plane/fin of primarily (but not exclusively) military aircraft (see also ‘roundel 1)')
homogeneous	Uniform in composition throughout the volume considered.
sidereal	relating to, or concerned with the stars
chondrite	a meteorite containing chondrules and other components produced in the solar nebula.
crater	A bowl-shaped depression formed by the impact of an asteroid or meteoroid
extraction	Extraction is the process of taking a solvent and using it to dissolve a compound from a mixture
photometer	An instrument for detecting and measuring light
making colours	See ‘colours 5)’.
ellipse	A flattened circle, or oval
kinetic energy	Kinetic energy is energy in motion
massive habit	This is a large crystal with no definite shape
orbit	the path of a celestial body through space
formula	This notation tells you the number of atoms in one molecule of a compound
inertial confinement	a method of studying and utilising plasmas in collision-types reactions
earth	intercepts a stream of
twilight	For technical definition, please follow this link to the U.S
promontorium pl. promontoria	A high point of land; headland.
galactic nucleus	The very centre of a galaxy, often containing a group of close together stars.
french revolution ~	a decimal timescale (10 equal hours or decidays per day) devised in 1790 by the French Academy after the French Revolution
lithium	Symbol:"Li" Atomic Number:"3" Atomic Mass: 6.94amu
deuterium	An isotope of hydrogen with one proton and one neutron in the nucleus.
equatorial telescope mount	An equatorial telescope mount is a complex device that is aligned parallel to Earth's axis and is pivoted at a right angle in order to follow the apparent motion of celestial objects (caused by the Earth's spinning)
i	In-phase
star	A self-luminous sphere of gas.
epimetheus	Epimetheus is one of the 18 moons of Saturn
free-fall contraction	Contraction of a cloud or system of particles by gravity only, unresisted by any other force.
satellite	Any smaller object that orbits a larger one.
gibbous	a phase of the Moon or other planetary object when it is more than half illuminated as seen by the observer
achromatic refractor	A type of refracting telescope that contains at least two lenses in order to correct for chromatic aberration
homosphere	All the lower layers of the terrestrial atmosphere in which the scale height is the same for all the constituants: and the pressure and concentration decrease rates follow the same law for all
force	A push or pull two or more objects.
terrestrial	smallest planets in the solar system, made primarily of rock.
monosaccharide	A monosaccharide is one sugar molecule
magnetosphere	Region around an object where the influence of the object's magnetic field can be felt.
velocity	Speed of an object; the change in position over time.
bayer name	The combination of a Greek letter and the name of a constellation (Alpha Centauri, Epsilon Orionis etc.) used to identify bright stars
meridian	the great circle (or, more usually, half of a great circle) passing through the N and S poles
magnetic confinement	a method of controlling plasmas and fusion reactions utilising magnetic fields - electromagnetic and other - to contain otherwise very hot and unstable material
temperature	A measure of the average energy of a molecule of a material.
centripetal force	The real force, opposite the fictitious centrifugal force, which keeps someone moving on a curved path from moving along a tangent to that path
small-angle equation	The equation giving the relation between the distance D of an object, its diameter d, and its angular size a - alpha (expressed in seconds of arc): a/206,265 = d/D
mercury	Symbol:"Hg" Atomic Number:"80" Atomic Mass: 200.59amu
solar	System are
tail	See ‘tongue(s)’.
bladed habit	This is a crystal shape that resembles a knife blade because is has very thin layers
civil twilight	For technical definition, please follow this link to the U.S
standard solution	This is a solution for which the scientist knows the concentration of solute and solvent.
flat field	An exposure taken of a constant source to counteract pixel variations in a CCD image
fixed	See ‘throughout'.
circumpolar star	a star that never sets but always stays above the horizon
opposition	When a surperior planet is directly opposite from the Sun in our sky, and is closest to the Earth.
earth	's
fft	Fast Fourier Transform
tectonics	The movement of plates of planetary crust that causes continental drift on Earth, as well as volcanoes and earthquakes.
co-ordinates	a system of measurements used to describe any point in two or three dimensions.
first canton	A term for that quarter of a flag which occupies the upper hoist - the first quarter, upper hoist or upper hoist canton – see ‘canton 1)' and ‘canton 3)' (also ‘hoist 1)').
comet	Solar system body, consisting of a solid nucleus made up of rock and ice
inertia	An object's resistance to any change in its motion.
ram	Random Access Memory.
earth	has been observed to fall towards the center of the
canting	An originally heraldic term for when the design on a shield or banner of arms forms a pun on the name or attributes of the entity or person represented – allusive arms or armes parlantes (see also ‘armorial bearings’).
palm	A term for the square or rectangular part of any flag that carries a schwenkel, or whose fly is divided into tongues (see also ‘crutch’ ‘indentation(s)’, ‘schwenkel’, ‘swallow-tail(ed)’, ‘swallow-tail and tongue’ and ‘tongue(s)’).
apochromat	A lens made of three pieces of glass (or other materials) with differing dispersions, chosen so as to reduce chromatic aberration to an even greater degree than in an achromat.
zero-age main sequence star	A newly formed star that has just arrived on the main sequence.
biological evolution	The natural development over time from simple to complex organisms, generated by mutations that change the gene structure and directed by natural selection of those individuals best-adapted to the enviroment.
celestial pole	The two poles (north and south) of the celestial sphere
naval crown	A crown generally (but not exclusively) formed from the sterns and square sails of ships placed upon a circle or fillet, and loosely based on an ancient Roman triumphal ornament of the same name (see also ‘civic crown’, ‘crown’, ‘fillet 3)', ‘mural crown’ and ‘yachting crown').
partial pressure	Partial pressure is the pressure of one gas in a system of two or more nonreacting gases.
black hole	An incredibly dense object whose gravity is so strong that not even light can escape from it
hubble law	The observed linear relationship between the distance of a galaxy and its velocity of recession
declination	In the Equatorial coordinate system, the north-south angle, measured along an hour circle, between a star and the Celestial Equator.
emc	Electro-Magnetic compatibility
orbital period	The time taken to go around one orbit.
saw-toothed	See ‘serrated’ (also ‘wolfteeth’).
keyhole	An area in the sky where an antenna cannot track a spacecraft because the required angular rates would be too high
big bang	The name scientists give to the events that started the universe.
rf	Radio Frequency.
stony iron	a meteorite which contains regions resembling both a stone meteorite and an iron meteorite.
cluster of stars	A group of stars that formed together and that have remained together due to their mutual gravitational attraction.
igneous rock	Rock crystallized from molten material.
parabola	a mathematical term for the conic section obtained by cutting a cone with a plane parallel to its generator (or "edge")
porphyritic	A geology term used to describe large crystals found in igneous rock.
oxygen	It is present in all known life forms
pan	Panchromatic
moon ~	a sundial calibrated in some way so that it can tell the time by moonlight
climate	The average weather conditions of a place or area over a period of years.
visible light	The range of wavelengths, or colors, of light that we can see with our human eyes.
micrometer	µm, 10 meter.
reflector	a telescope in which the main light gathering element is a mirror
subfragmentation	Breakup of a contracting cloud into smaller condensations.
albedo	This term is a unit-less measure that refers to the how much an object diffusely reflects light from the sun
vertical flag	See ‘banner 2)'and ‘hanging flag' (also ‘vertically hoisted flag').
lacus	"Lake"; small plain.
f	Force.
matter	In his famous equation E=mc2 Albert Einstein stated that mass (m) is equivalent to energy (E) - the two parameters are related via the speed of light (c).
e pennant	1) See ‘battle efficiency pennant'
unequal ~	an hour system where the duration of an hour depends on the date and is different from day-time to night (except at the equinoxes)
gravitation	A process used to separate compounds that have different densities
vapor pressure	A property that is unique to each liquid
fault	A geological term that refers to a fracture or a break in a hard surface like the Earth’s crust
false color	A technique scientists use to help them see details in images of objects
scarp	A line of cliffs produced erosion or by the action of faults.
sun	Our star, the center of our solar system
nucleic acid	The large molecule on which genetic material is based.
irregular galaxy	A type of galaxy that does not have a regular shape
launching flags	Those flags flown from a vessel that is being launched prior to fitting out, and which in naval usage are generally (but not invariably) of a prescribed type and sequence (see also ‘dressing lines’ and ‘flag exchange’.
composition	What an object is made of.
igneous rock	a rock that was once molten.
atom	All matter is made up of tiny atoms
ir	Infrared
labyrinthus pl. labyrinthi	Complex of intersecting valleys.
spectroscopy	The technique of observing the spectra of visible light from an object to determine its composition, temperature, density, and speed.
magnetic field lines	imaginary lines that indicate the strength and direction of a magnetic field
astronomy	The study of the Universe, and its contents.
cosmological constant	Term that can be added to the equations of general relativity to give a static solution.
aromatic hydrocarbon	Hydrocarbon compounds in which the carbon atoms are connected by a ring structure that is planar and joined by sigma and pie bonds between the carbon atoms
depth	See ‘width 1)’.
retrograde	Motion which is backwards as compared to the standard direction
angstrom	abbreviated Å
solar compass	an instrument for direction finding which uses dialling principles
gregorian calendar	A calendar in which normal years have 365 days, leap years have 366 days, and leap years are usually held every four years, but are not held in century years that are not divisible by 400
eclipse	An alignment of two bodies with the observer such that either the nearer body prevents the light from the further body from reaching the observer (strictly speaking, these are occultations), e.g
big bang	The theory that suggests that the universe was formed from a single point in space during a cataclysmic explosion about 13.7 billion years ago
earth	, the more it tends to be red-shifted.
apastron	In an orbit around a star, the furthest point from the star.
entropy	The measure of disorder in a physical system, which always tends to increase with time
bar	A unit of measure of atmospheric pressure
daytime	that period of a day between sunrise and sunset.
meteoroid	a chunk of space debris
parallel	Two lines are parallel if they remain at a constant distance away from each other along their lengths.
international date line	the line from the N to S poles, approximately following the 180º line of longitude, through which the date alters by one day (positively if travelling from W to E)
homogeneous	Uniform throughout space.
kreep	Elemental composite materials used by scientists as a chemical tracer, consisting of potassium (K), Rare Earth Elements and phosphorous (P).
exploration	to search in unknown places.
degenerate energy state	A set of energy states which have exactly the same energy, and are therefore indistinguishable from each other.
white light	visible light that includes all colors and, therefore, all visible wavelengths.
oxide mineral	A mineral that is made up of compounds with an oxygen atom bonded to a metal
uv	Ultraviolet
nutation	A small nodding motion in a rotating body
accolé	See ‘gorged'.
pulsar	a rapidly spinning neutron star that sends out pulses of radiation at regular intervals
rotation	turning around a center or an axis, or to turn in a circle.
overdensity	An area in the Universe with a slightly higher density than average, which may condense to form structure.
ionosphere	Gas consisting of charged particles (ions and electrons) that mingle with the thermosphere to form the atmosphere of high altitudes.
sidereal ~	[τ, SDT] "astronomical or star time"
ftp	File Transfer Protocol (server)
avhrr	Advanced Very High Resolution Radiometer
rock	A rock is a group of minerals in a mixture
fr	Full Resolution
p-p chain	See Proton-Proton Chain
mantle	The layer between the core and the crust of a planetary body.
acid rain	Acid rain is polluted and harmful to the environment
centre of mass	The point in a body, or system of bodies, at which the whole mass of the system can be assumed to be concentrated.
officer’s flags	In US usage and in some others, those flags that are flown by the past and present officers of a club, especially of a yacht or boating club – yacht officers flags (but see ‘broad pennant 3)’ and ‘officer's pennants’).
atbd	Algorithm Theoretical Basis Document
planum	a high plain or plateau.
rna	The molecule that assembles proteins from DNA instructions.
mgso	(Obsolete
earth	or
emission spectrum	An emission spectrum (also called a bright-line spectrum) is a discontinuous spectrum (discrete bright bands) that is emitted by atoms or molecules
fatty acid	A fatty acid has a carboxylic acid on a long chain of carbon atoms
halo	See ‘nimbus’
obliquity	the angle of tilt of a planet's axis of rotation
noon cross	a cross shape often seen instead of XII on the noon line of dials
caldera	Created when the top of a volcano collapses into a crater.
day	The period of rotation of the Earth.
galaxy clusters	A concentration of galaxies held in one large region of space by gravity, with anywhere from a few dozen to thousands of members.
post meridiem	the portion of the day between noon and midnight.
esl	Expert Support Laboratory
meteorite	a meteoroid that enters the Earth's atmosphere but survives to hit the ground
heresy	Views that go against those of the established church.
impact event	A collision between two solar system bodies that releases exceptionally large amounts of energy
meteor stream	See meteoroid swarm.
event horizon	Imaginary surface at the distance from a black hole where the escape velocity is the speed of light
fr	Fast Registration
axis	an imaginary line about which an object rotates
helium	A light gas.
equilibrium constant	Value that expresses how far the reaction proceeds before reaching equilibrium
event horizon	The imaginary surface of a black hole
bandera de guerra	See ‘war flag 1)’ and ‘war flag 2)’.
angular momentum	The tendency for bodies to continue revolving or rotating due to its inertia.
diastolic	A measurement of the amount of pressure on the walls of blood vessels when the heart is at rest.
stellar	Anything having to do with stars.
declination	Arc of a meridian between a point on the surface and the point on the equator.
falling diagonal	See 'descending diagonal'.
earth	. Not to be confused with
astrophysics	because observing their mutual orbits allows their mass to be determined
cap badge	See ‘badge 3)’.
half-life	The half-life of a radioisotope is the amount of time it takes for half of the radioisotope to decay.
james union	An unofficial name for the 1606 pattern British union flag (see also ‘British flag’, ‘His Majesty's jack', ‘interlaced' ‘conjoined’ and ‘union jack’).
europa	Second Galilean and fourth largest moon of Jupiter
saf	Satellite Applications Facility
indented edge	See ‘scalloped 1)'.
nobelium	Symbol:"No" Atomic Number:"102" Atomic Mass: (259)amu
small circle	a circle on the surface of a sphere whose centre does not coincide with that of the sphere (and hence it must always have a smaller diameter).
mil	unit of angular measurement used in some military equipment, e.g
periodic table	This famous table organizes all of the known chemical elements by their atomic number
cosmogony	The study of the origin and early evolution of an astronomical system; usually, of the Universe or Solar System, but occasionally of specific systems, such as the Earth-Moon system.
veteran’s flag	The flag of an organization representing the veterans of a particular, service, war, campaign, or unit
wavelength	The distance that a wave from a single oscillation of electromagnetic radiation will propagate during the time required for one oscillation .
icrs	International Celestial Reference System
niobium	Symbol:"Nb" Atomic Number:"41" Atomic Mass: 92.91amu
hour line	the line on a dial plate indicating the shadow position at a particular time (includes fractional as well as whole hours)
earth	is a
blood pressure	The pressure of blood on the walls of blood vessels.
ideogram	See ‘mon 1)’ and its following note.
map	Microwave Anisotropy Probe
sc	Steering Committee.
schwarzschild radius	The radius corresponding to the event horizon of a black hole, proportional to the mass of the black hole.
antarctic circle	the parallel of latitude at 66° 34' S
aberration of light	The aberration of light is a phenomenon in which light appears to be slanted (the angle at which the light appears to be coming is different than the angle at which it's actually coming) if the observer is in motion
fictitious flag	A flag – or the illustration of a flag - that purports to represent an actual entity or person, but for which no evidence of any such use by that entity or person exists – but see ‘flagoid’ (also ‘false flag 1)’, ‘fictional flag’ above, ‘flag of pretence 1)' and ‘replica flag').
crystal lattice	A crystal lattice is a very exact organization of atoms that allows for a specific place for every molecule or atom in the solid
skeleton equation	A chemical equation that is not balanced, with an unequal number of atoms on each side of the reaction
nova	a star which temporarily increases in brightness; thought to be caused by the inflow of matter from a star to its white dwarf companion
quarter-moon	See ‘crescent 1)'.
gos	Global Observing System
direct ~	a vertical dial which directly faces one of the cardinal points of the compass e.g
organic molecule	Molecule based on the carbon atom, usually large and complex, but not necessarily part of living organisms.
aberration	An optical effect which degrades an image.
astrobiology	Astrobiology is the science that addresses the question of whether or not there is life in space, and if so, then what it its origin, distribution, and evolution.
quartered diagonally	In vexillology, a phrase that may be used in place of the heraldic term per saltire - see ‘per saltire 1)'.
decay	Change of an element into a different element, usually with some other particle(s) and energy emitted.
emission	Release of electromagnetic radiation from matter.
orogeny pl. orogenies	The process of forming mountains, usually as a result of the folding of the surface of a region.
blackbody	An object which does not reflect any radiation, it is all absorbed.
flat universe	what
stratosphere	Region of the atmosphere between the troposphere and the mesosphere, at an approximate altitude of 12 to 50 kilometers.
jerusalem cross	A cross-potent cantonée - see ‘cross cantonée’ and following note in ‘appendix VIII’, also ‘cross potent’ in ‘appendix VIII’.
orbit	The bursts may last from as little as a hundredth of a second up to 90 minutes
cape canaveral	Cape Canaveral is located in Florida at the site of the John F
doppler shift	A change in the colour of light from an object that is moving
onomast	See ‘name pennant’.
equator	The line where a plane that is perpendicular to a bodies axis of rotation, and passes through its centre, crosses the surface of the body.
tellurian	a demonstration model, similar to an orrery, but showing the Earth-Sun system, or the Earth-Sun-Moon system
intensity	The strength of radiation
parent ~	a form of analemmatic ~, with the dial plane parallel to the Earth's axis so that the ellipse of hour points becomes a segment
cantabrian labarum	The flag of the Cantabrian independence movement showing a wheel-like emblem that is considered symbolic of the ancient Cantabrians of Northern Spain.
quasar	A very distant, immensely bright object.
light curve	A plot of the brightness of a star (or any astronomical object) versus time.
radiant	The point from which meteors appear to eminate in the sky
c	The speed of light, 299,792 km per second.
angstrom	commonly used to measure the wavelength of light; equal to 10-10 meters
dexter	The heraldic term for the right hand side of a flag or shield from the point of view of the bearer, or the left hand side from the point of view of an observer (see also ‘sinister’).
radial velocity	The velocity component along the line of sight toward or away from an observer
apse	One of the two ends of the major axis of an ellipse
nuclear fusion	The merging of light atomic nuclei into heavier atomic nuclei, with the release of particles and radiation.
specific heat	The amount of heat it takes for a substance to be raised 1°C.
norad	North American Aerospace Defense Command
angstrom	An Angstrom is equal to one ten billionth (1 x 10-10) of a meter
sidereal	Of, relating to, or concerned with the stars
inescutcheon	The heraldic term for one shield appearing within another (usually – but not invariably - at its centre point) or on a banner of arms (see also ‘banner of arms', ‘coat of arms’ ‘escutcheon’, ‘escutcheon of pretence 1)', ‘overall’ and ‘quartering 1)’).
basic	Having the characteristics of a base.
hv	Horizontal-Vertical (polarisation)
nrsc	National Remote Sensing Centre
thorium	Symbol:"Th" Atomic Number:"90" Atomic Mass: 231.04amu
compendium	normally used to describe a collection of scientific instruments in one case
julian day	The day beginning at noon, Greenwich time, and ending at the next Greenwich noon.
closure	A mathematical term which says that if you operated on any two real numbers A and B with +, -, * or /, you get a real number.
saint george's canton	See ‘canton of St
compound	A substance composed of two or more atoms bound by chemical forces.
lanceolate	(adj) A term used that may be used to describe a rounded fly – but see ‘ogival’ (also ‘descate’, ‘guidon 3)’, ’fly’, ‘standard 4)’ and ‘standard 5)’).
betelgeuse	A supergiant star also called Alpha Orionis
thermal equilibrium	A balance between the input and outflow of heat in a system.
earth	-size "pimples" to swollen scars halfway across the surface
jansky	See unit of solar flux.
opacity	The extent to which gaseous (or other) material absorbs light.
equinox	the two points at which the Sun crosses the celestial equator in its yearly path in the sky
drake equation	An equation developed by astronomer, Frank Drake, in 1961 that estimates the number of civilizations in our Milky Way galaxy that are advanced enough to communicate with us
jelloped	The heraldic term used to describe the wattles and comb of a domestic fowl when they of a different tincture from its body – jowlapped - but see ‘wattle(d) 2)’ (also ‘appendix V’, ‘armed 2)’, ‘attired’ ‘beaked’, ‘gorged’, ‘langued’, ‘membered’ and ‘tincture’).
refracting telescope	A type of telescope that uses lenses to collect and focus light from astronomical objects
palewise	See ‘in pale’.
compounds	It has an important function in the neurological system in animals (including humans).
planetesimal	A solid object that is believed to exist in protoplanetary disks and in debris disks
light year	or 3.1 x 1016 metre (see scientific notation)
anisotropic	Something that is not the same in every direction.
pulsar	A rapidly rotating neutron star with a strong magnetic field, observed to emit pulses of radiation.
differential rotation	The effect where different parts of a non-solid body, such as a star or the atmosphere of a planet, turn at different speeds.
zulfikar	A term for the split-bladed or double-pointed "Sword of Ali" (originally a symbol of - the Janissaries - an elite military formation of the Ottoman Empire) that has appeared on several Arab flags (see also ‘shahada' and ‘takbir').
kent vane-fly	See ‘bob’.
kilovolts	one thousand volts
solar atmosphere	the atmosphere of the Sun
hertz	abbreviated Hz
time	The property that stops all events happening at the same point from coinciding.
galaxy evolution	The study of the birth of galaxies and how they change and develop over time.
parallax	The shift of an object when it is viewed from two different places
sec	Second.
carbon dioxide	A gas with no colour or smell that doesn't burn and is formed when we breath.
proton	's electrical charge has the same
conjugate base	A conjugate base is a molecule that is created when you start with an acid and remove a proton.
aircraft marking	In UK and some other usage, a collective term for the markings of nationality and identification on the wings, fuselage and tail plane/fin of primarily (but not exclusively) military aircraft – but see ‘fin flash' and ‘roundel 1)' (also ‘aircraft insignia' above, ‘fuselage markings 1)' and ‘wing marking(s) 1))').
am	Ante Meridian
terrella	from the Latin for "little globe"
minute	See Arcminute.
photometry	The measurement of the amount of light, either total or in different specified colors, coming from an object.
solar	masses, the maximum mass a dying
chasma pl. chasmata	A deep, elongated, steep-sided depression.
astronautics	Astronautics is the science of the design, construction, and operation of spacecraft.
ionosphere	A region of the Earth's atmosphere.
hydroxyl group	This is a side group which is one hydrogen atom bonded to one oxygen atom
greenhouse effect	Heating of an atmosphere by absorption of outgoing infrared radiation.
ephemeris	a table of data arranged by date
binoculars	Two small telescopes put next to each other so that both eyes can look at an object at the same time.
cdr	GCF central data recorder.
iron meteorite	a meteorite which is composed mainly of iron mixed with smaller amounts of nickel.
black hole	the theoretical remains of a supermassive star that has exploded and collapsed in on itself
redshift	a shift in the lines of an object's spectrum toward the red end
national ornament	A decorative strip (usually placed along he hoist of a flag) intended to represent a folk or traditional element of national culture, and particularly prevalent among Eastern Slavic and Siberian states such as Belarus, Kazakhstan and Mariy El – see ‘folklore ornament'.
tenné	A heraldic term for the colour orange (see also ‘Appendix III’ and ‘rule of tincture’).
quarks	Quarks are the fundamental building blocks of protons and neutrons which are the components of atomic nuclei.
armalcolite	Fe-Mg titanate, FeMgTi2O5, found in lunar rocks
gpcp	Global Precipitation Climatology Project
above	1) In vexillology a term used when a charge (or charges) is (or are) placed on top of, or immediately above another – but see ‘above 2)' and ‘surmounted by 1)' (also ‘charge 1)')
wedge wavy	See ‘piles(s) wavy 1)’.
tide	The phenomena of varying coastal water levels, caused by the gravitational pull of the Moon and the Sun.
quinterfoil	See ‘cinquefoil'.
h	Hour.
lunar	mountains and craters
dilution	Dilution occurs when a solution with a known concentration (standard solution) has more solvent added
solar	masses that has evolved off the
butterfly diagram	A diagram showing how the latitudes of sunspots tend to decrease during a solar cycle
atomic nucleus	The dense core of every atom
chemistry	The study of the composition, structure, properties, and reactions of atoms and molecules.
neodymium	Symbol:"Nd" Atomic Number:"60" Atomic Mass: 144.24amu
radio waves	Radiation with the lowest amount of energy
light speed	299,792 km per second, the constant c.
big bang	According to the 'standard' cosmological model, a simultaneous explosion throughout space that is at the origin of our universe.
centrifugal force	The fictitious force which occurs when moving along a curved path
fluctus	Flow terrain.
volcano	(1) A vent in the planetary surface through which magma and associated gases and ash erupt
atom	consists of a tightly packed
condensation	A change of state from gas to liquid.
dioptric	Refracting telescope
propellant	Product composed of one or several ergols, capable of producing the energy required to propel a rocket engine, via chemical reaction.
horizon system	A spherical coordinate system in the sky, based on the direction of gravity, and the division of the sky into visible and non-visible portions by the skyline
poh	pOH is the measure of hydroxide ion concentration
states of matter	Solid, liquid, gas and plasma
descate	(adj) A term used to describe a rounded (or lanceolate) fly into which a ‘V’ shaped notch has been cut, and a shape often seen in UK cavalry guidons – cloven descate or rounded swallowtail (see also ‘fly 1)’, ‘guidon 2)’, ‘hussar cut’, ‘lanceolate’, ‘pennant’ and ‘swallow tail(ed)’).
star of david ~	a monumental dial similar in concept to the cross dial, except that the six-pointed star with 60º angles gives opportunities for numerous dials.
lithium	third element in periodic table - used in liquid form to contain magnetically confined deuterium-tritium fusion, generating more tritium as the produced neutrons interact with it
rhodium	Symbol:"Rh" Atomic Number:"45" Atomic Mass: 102.91amu
transducer	Device for changing one kind of energy into another, typically from heat, position, or pressure into a varying electrical voltage or vice-versa, such as a microphone or speaker.
season	summer autumn, winter, spring
takbir	A term for the Arabic inscription Allahu Akbar or “God is Great” that has appeared on several Arab Flags and can currently be seen on those of Iran and Iraq (see also ‘shahada’ and ‘zulficar’).
apollo missions	NASA's Apollo missions (1961 to 1975) were the only missions to send people to the moon
cycloid ~	a variation of the standard polar dial in which the gnomon has a cycloid shape, with the result that the hour lines are equally spaced.
orbit	The elliptical path of an object that is gravitationally bound to another object.
eccentricity	The distance between the foci of an ellipse divided by the major axis.
chromatic aberration	An unwanted effect seen in refracting telescopes, caused by the fact that different wavelengths of light are refracted by different amounts by the lens and so are focussed at slightly different places
hydrogen	in which the nucleus contains one proton and two neutrons
igneous rock	Rock formed from cooled and hardened magma.
dna	A long, replicating molecule, shaped like a twisted ladder, that is the basis of the genetic code
f10.7	Decimetric index measurement of the solar emission flux at 10.7 cm (expressed in 1022 W m-2 Hz-1)
transponder	Electronic device which combines a transmitter and a receiver.
energy	The ability to do work.
sirtf	Space Infrared Telescope Facility.
globular cluster	A roughly spherical collection of stars, numbering from a few tens of thousands to more than ten million stars, scattered over a region a few tens of light-years in diameter
tau cross	See ‘cross tau’ in ‘appendix VIII’.
planet	Scarp A line of cliffs produced erosion or by the action of faults.
mopitt	Measurements Of Pollution In The Troposphere
radiation	Energy released as either waves or particles.
mass number	The number of protons and neutrons in an atom.
geneva convention flag	See 'safe conduct flag 1)'.
fossa pl. fossae	Long, narrow, shallow depression.
equinox	The equinoxes are times at which the center of the Sun is directly above the Earth's equator
tanzenspitzkreuz	The German term for a “Latin cross fitchy” – see ‘cross fitchy’ and ‘Latin cross’ in ‘Appendix VIII’.
nitrogen	A non-metallic element, usually found in the form of an odourless, colourless and unreactive gas, N2, which makes up about 78% of the Earth's atmosphere.
quarantine flag	In current usage, a plain yellow flag (‘Q' Quebec in the International Code of Signal Flags) that is flown by a vessel arriving in port stating that it is healthy and requires medical clearance or free pratique – a pratique flag but see note below (also ‘International Code of Signal Flags').
canyon	A large, long split in the ground.
secondary craters	Craters produced by the impact of debris thrown out by a large impact event
fission chain reaction	Nuclear power plants use nuclear reactors to produce electricity
azimuth	The coordinate which describes an object's location in relation to its compass direction, expressed in degrees between zero and 360.
cct	Computer Compatible Tape
department pennant	See ‘service pennant’.
earth	23 hours, 56 minutes, 4.091 seconds to complete one full turn relative to the stars, versus exactly 24 hours relative to the Sun
wavelength	the distance from crest to crest or trough to trough of an electromagnetic wave (see electromagnetic radiation) or other wave.
energy	In physics, a specific quality equal to work or the ability to do work
rayonné	See ‘radiant’.
armored chondrule	Chondrule covered on its surface by a layer of nickel iron.
astronomer royal	The Astronomer Royal is appointed by the Queen (or King) of England to be custodian of the Greenwich Observatory
'f' cross	See ‘one-and-a-half armed cross’.
second	See Arcsecond.
image	A likeness of a thing or a place
classification	Arranging into groups
circumpolar	An object that does not set from its observer's latitude.
neutron	One of the particles found in the nucleus of an atom
rrr	Rolling Review of Requirements
cohesion	Cohesive forces of attraction happen between molecules of the same type
equinoctial ~	(pron
micrometeorites	Extremely small space rocks
mass	The amount of matter in an object.
blue moon	1
velocity	A vector that denotes both the speed and direction a body is moving.
mass	a measure of the total amount of material in a body, defined either by the inertial properties of the body or by its gravitational influence on other bodies.
corrosive	Causing constant damage.
solute	The substance (solid, liquid, or gas) dissolved in a solution, for example, the salt in saltwater.
dorsum pl. dorsa	Ridge.
cimss	Cooperative Institute for Meteorological Satellite Studies
melting point	The melting point is the temperature at which a substance changes state from solid to liquid
meteor	A small interplanetary body that burns up in Earth's atmosphere
telescopes	See http://sci.esa.int/ngst/
macrospicule	Solar matter ejected permanently between the supergranules, in the form of proton and electron tongues.
mantling	A heraldic term for the decoration resembling drapery in a coat of arms, and attached to the helmet by a torse (see also ‘Appendix IV’, ‘armorial bearings’, ‘coat of arms’ and, ‘helm’ – for information on torse see ‘wreath 2)’).
iron	A metal that causes rust.
asteroid	A small rocky object in the Solar System
molecular formula	Shows the number of atoms of each element present in a molecule.
arc degree	A unit of angular measure in which there are 360 arc degrees in a full circle.
photon	A component of light which is considered a particle with zero mass.
ejecta	Material from beneath the surface of a body such as a moon or planet that is ejected by an impact such as a meteor and distributed around the surface
solar system	The Sun and all bodies orbiting around it.
gene	The minimum amount of genetic material that expresses a characteristic of living organism; a sequence of several hundred bases along DNA molecule.
cosmology	The study of the Universe, its structure and evolution.
in saltire	The heraldic term used when two separate objects or charges are placed across each other diagonally on a flag, shield or banner of arms - saltirewise (see also ‘banner of arms', ‘saltire’ and ‘per saltire’.
gravity	a mutual physical force of nature that causes two bodies to attract each other.
ssr	Satellite System Receiver
union standard	In British military usage, a term for one of three such standards each carried by the Life Guards and the Blues and Royals - the Household cavalry - and the equivalent of a normal cavalry guidon or infantry colour (see also 'colour 2)', 'colours 2)' and ‘guidon 2)’ and ‘sovereign's standard').
anisotropy	Anisotropy is a state in which a physical characteristic (like the temperature of the cosmic background radiation) varies in value along axes in different directions - a physical measurement made in one direction differs from the measurement made in another direction
axis	Also known as the poles, this is an imaginary line through the center of rotation of an object.
yellow dwarf star	Any small yellow star like the Sun
navy flag	See ‘branch of service flag’ (also ‘armed services flag’).
centre of gravity	The point in a body, or system of bodies, at which all external forces can be taken to act
radium	Symbol:"Ra" Atomic Number:"88" Atomic Mass: 226.03amu
advent cross	See ‘cross tau' in ‘appendix VIII'.
earth	's gravitational pull.
sedimentary rocks	A type of rock formed from hardened deposits of sediments.
transmit	To send from one person or place to another
lidar	LIght Detection And Ranging
escape velocity from earth	11.2 km/s; Mach 34.
angular momentum	Angular momentum is a momentum-like quantity associated with a circular motion around an axis of rotation
gallium	Symbol:"Ga" Atomic Number:"31" Atomic Mass: 69.72amu
daylight saving time	[DST] civil time during the summer in much of the USA (and some other countries) obtained by advancing clock time one hour from local standard time
osi	ISO's Open Systems Interconnection protocol suite.
sun clock	see solar chronometer, dial (types of).
dwarf star	Supergiant star.
fusion	a process where nuclei collide so fast they stick together and emit a great deal of energy
caldera	a large, basin-shaped volcanic depression that is more or less circular in form
galaxy	to the
ictsw	Inter-programme Coordination Team on Space Weather
efficiency	How well something works.
balanced equation	A balanced chemical equation has equal numbers of atoms on each side of the equation
tektites	Objects made from natural glass that are created from the impact of meteorites
queue fourché	See ‘double queued'.
plutonium	Symbol:"Pu" Atomic Number:"94" Atomic Mass: (244)amu
charge	Describes an object's ability to repel or attract other objects
atmosphere	Layer of gas confined close to the planet's surface by the force of gravity.
kommandowimpel	See ‘masthead pennant 1)’.
euv	Extreme Ultra Violet
pe	Post Encounter phase in flyby mission operations.
unit	A well-defined entity for representing a measurable quantity.
telegraph flag	In British RN usage now obsolete, the flag invented by Admiral Popham and raised prior to a signal hoist to indicate whether the following flags were to be deciphered using a signal book or by his vocabulary code (see also ‘code pennant', 'preparative' and ‘signal flag').
oxygen	Silicates are found in nature as the mineral quartz in its various forms
dichotomy	The phase of a planet or the Moon, when exactly half lit; more often called "quarter" phase.
tantalum	Symbol:"Ta" Atomic Number:"73" Atomic Mass: 180.95amu
maria	Plural form of mare.
continuous spectrum	A spectrum made up of all wavelengths, without emission or absorption lines or bands.
sable	The heraldic term for the colour black (see ‘Appendix III’ and ‘rule of tincture’).
maria	Dark, young, lowland plains on the moon, consisting of basaltic lava with few large craters.
galaxy cluster	A group of galaxies held in proximity due to their mutual gravitational attraction
abeyance	See ‘in abeyance'.
commensurate	Having a common measure, usually as the ratio of two small whole numbers
astronomical unit	A unit of length equal to the average distance of the Earth from the Sun
arcminute	Measure for small angles
ellipse	A flattened circle
astronomy	The study of all matter and energy in the universe.
aurora borealis	The auroral displays visible in the northern hemisphere.
average orbital	speed around the Sun: This is a measure of how fast a planet moves through space, in kilometers per hour.
admiralty crown	An alternative British term for the naval crown - see ‘naval crown'.
infinity	Space, time or a quantity which has no bounds and goes on forever.
linea pl. lineae	A dark or bright elongate marking; may be curved or straight.
rampant	See ‘Appendix V’.
aas	American Astronomical Society.
aurora australis	also known as the southern lights, this is an atmospheric phenomenon that displays a diffuse glow in the sky in the southern hemisphere
schmidt cassegrain	A catadioptric telescope that combines a cassegrain reflector's optical path with a Schmidt corrector plate
badge pennon	The term for a medieval lance pennon (usually carried by those mounted men-at-arms who were non-armigerous) that displayed a heraldic badge against livery colours – but see ‘pennoncel' (also ‘armigerous', ‘banneret 2)', ‘Badge in Heraldry', ‘lance', ‘livery colours 1)', ‘pennon 3)') and ‘pennoncier'.
saint james’ cross	See ‘cross of Santiago’ in ‘appendix VIII’.
earth	and a radius 9.45 times the radius of the Earth
raguly	A heraldic term meaning any number of small regular projections set an angle on both sides (or on one side only) of a bar, cross or saltire and thought to represent a roughly trimmed branch – see ‘ragged cross' (also ‘saltire').
vergette	See ‘paly’ in Appendix VI.
desiccant	A desiccant goes through a process of deliquescence to dry an area or volume of air
coronal mass ejections	are huge bubbles of gas threaded with magnetic field lines that are ejected over the course of several hours.They are often associated with solar flares and prominence eruptions.
degenerate electron pressure	The pressure exerted by degenerate electrons (neutrons).
northern hemisphere	The upper half of our planet where the UK and Hawaii can be found.
diffraction ~	a dial invented in 1999 by M
electron	One of the parts of the atom having a negative charge
torr	Torr is a measurement of pressure
unicolour/unicoloured	See ‘monocolour’.
imperial dragon flag	See ‘dragon flag 2)’.