Lunar Vocabulary

I always tell my students that in order to fully understand a topic of study the first place you need to start is with vocabulary. So this is a list I have begun to further my understanding of lunar geology.

waning -to decrease in illumination from the full moon
waxing - to show a progressively larger illuminated area of the moon
libration - the orbital conditions that make it possible to see more than 50% of the moon
mare - large dark basaltic planes on the lunar surface
lunar eclipse - the blocking of the sun's rays by the Earth from reaching the moon
gibbous- more than half
penumbra - the zone where the Earth blocks part of the Sun's rays from reaching the moon
umbral - region where all direct sunlight is blocked by Earth
regolith - a layer of loose, heterogenous material covering rock
Updated October 17
chondrule-a roughly spherical aggregate of coarse crystals formed from the rapid cooling and solidification of a melt at about 1400 degrees celsius
chondrite - the most primitive type of rock available for study, 4.5 billion years old
solar nebula- the rotating flattened cloud of gas and dust from which the sun and the rest of the bodies in the solar system formed about 4.56 x 10^9 years ago
accretion-the increase in mass of a celestial object by the collection of surrounding interstellar gases and objects by gravity
achondrite-a stony meteorite that contains no chondrules
asteroid-any of the numerous small celestial bodies that revolve around the sun with orbits between Mars and Jupiter
silicate-any of the numerous compounds containing silicon, oxygen and one or more metals
magnetosphere - an asymmetrical region surrounding the Earth, extending form about one hundred to several thousand kilometers above the surface, in which charged particles are trapped and their behaviour is dominated by Earth's magnetic field
planetesimals - bodies ranging in size from metres to hundreds of kilometers in diameter that formed during the process that formed the planets by accretion
rarefaction - a decrease in density and pressure in a medium, caused by the passage of a soundwave
breccia-rock composed of sharp-angled fragments embedded in a fine grain matrix
impact basins - impact structures exceeding 300 km in diameter
ejecta - thick, continuous layer of ejected geological material
regolith - loose fragmented pulverized rock covering the lunar surface
central uplifts - mountains formed because of the huge increase and rapid decrease in pressure during the impact event - only occur in craters that are larger than 40 km diameter
rays - bright streaks starting from a crater and extending away for great distances
fire fountaining - a jet like eruption of lava that issues vertically from a volcanic vent or fissure
magma - molten rock, crystals and dissolved gases
volcanoes -
magma chambers -
dike - body of magma moving through a sheet-like, vertical or nearly vertical fracture
rift zones - regions of dike injections
vessicles - round holes formed in volcanic rocks due to gases such as carbon monoxide or carbon dioxide
pahoehoe flow -
a'a flow -





to be continued....