Moon is the only known natural satellite of the Earth. The Moon's mean distance
from Earth is 384,403 km. The lunar equatorial diameter is 3,476 km, more than
a quarter of the Earth's diameter. However, its volume is only 2% of Earth's,
and the difference in mass is even greater. Yet the Moon is one of the largest
planetary satellites (moons) in the entire Solar System (fifth largest) and
relatively, i.e., relative to its parent planet, it is the largest ever.
Meteorites originating from the Moon are classified as differentiated achondrites.
Lunaites - lunar meteorites formed by the impact of another body on the surface of the Moon. The lunar material was ejected into space after the impact and only a small portion hit the planet Earth. In simple terms, the material of which the lunar meteorites are composed is molten, brecciated rock, formed after an impactor hit the lunar surface.
About 80 percent of lunar meteorites are generally anorthositic or feldspathic. These rocks contain varying amounts of anorthite, olivine; orthopyroxene, clinopyroxene (pigeonite, ferropigeonite, diopside, augite, subcalcic augite), silica; oxides (chromite, Ti-chromite, Cr. ulvöspinel, ilmenite, rutile, Cr-pleonaste, baddeleyite), K-bearing glass, and small amounts of kamacite and troilite.
About 15 percent of the lunar meteorites are broadly basaltic or gabbroic. They contain major calcareous plagioclase and clinopyroxene (augite, subcalcareous augite, pigeonite), accessory silica (probably tridymite), rare olivine, and trace amounts of metallic Fe-Ni and troilite.
About 5 percent of the lunar meteorites are mixed or polymict breccias. Their mineral constituents are a combination of those in anorthositic and basaltic lunar meteorites.