Lunar Meteorite | NWA 12691 — A Pocket-Size Piece Of The Moon, Interior And Exterior Revealed

This is a complete lunar meteorite fragment, i.e., a chunk of the Moon ejected into an Earth crossing orbit following an asteroid impact. Most of the Moon’s craters are the result of such ancient impacts. The Moon is among the rarest objects on Earth — less than 1,200 kilograms is known to exist. The 382 kilogram portion of this amount recovered from the Apollo missions is untouchable to the public. As for the lunar meteorites, a good deal of that is also untouchable as a result of its residency in the world’s great museums. This meteorite’s lunar origin was determined by several scientists whose work is vetted by a panel of colleagues prior to publication in the Meteoritical Bulletin, the journal of record.

Lunar specimens are identified by specific geological, mineralogical, chemical and radiation signatures. Many of the common minerals found on Earth’s surface are rare on the Moon; in addition, lunar rocks contain gases originating from the solar wind with isotope ratios that are very different than the same gases found on Earth. As would be imagined, some of the lunar samples returned to Earth by the Apollo astronauts closely resemble some lunar meteorites — and this is one such example. The surface of this sample reveals abundant anorthosite inclusions and other clasts suspended in dark charcoal-hued lunar regolith.

The analysis of this meteorite was led by Dr. Anthony Irving, whose findings underwent peer review by the Nomenclature Committee of the Meteoritical Society. The analysis and classification was published in the 108th edition of the Meteoritical Bulletin — the official registry of meteorites.