Are lunar meteorites really pieces of the moon?
This piece of the moon comes from the lunar meteorite known as NWA 10782. Specimen NWA 10782 is a lunar meteorite that has been analyzed and classified by researcher R. Hewins at the Muséum d'Histoire Naturelle de Paris. The original specimen from which the end you receive was cut is a moonstone before classification: a reference sample of 0.977 g and 6.88 g is available at the Muséum d'Histoire Naturelle de Paris.
What is a lunar meteorite?
A lunar meteorite is a lunar rock discovered on Earth that was ejected from the Moon when an asteroid struck its surface.
How do we know these meteorites come from the moon?
The chemical and isotopic compositions and minerals that make up these meteorites are similar in every way to the samples brought back from the Apollo missions.
How many of them are there?
Currently, of the approximately 30,000 meteorites recorded, only 50 are recognized as authentic lunar rocks. This is why it is claimed that lunar meteorites are extremely rare, excessively rarer than gold and diamonds.
From which part of the Moon do they come exactly?
There are mainly two types of lunar meteorites. The first one has the composition of the constituent rocks of the bright parts of the Moon's surface. These clear parts of the Moon are called breccia rocks because they are very fragmented and compacted by the multiple impacts since the formation of the Moon (in English "highland regolith breccia"). The second concerns some basaltic lunar meteorites from the dark parts ("basalt pond" in English referring to lunar seas).
What about this meteorite, NWA 10782?
NWA 10782 is a crystalline impact breccia rock. It is therefore what is called a "Regolith Breccia". The rocks here were completely melted down when an asteroid hit the Moon. A second impact ejected this rock, which also contains basalt residues, while the main composition is anorthotic (more precisely: "Highland Regolith Breccia Lunar Meteorite").
Where, when and how were these different lunar meteorites discovered?
All lunar meteorites have been discovered in Antarctica or in the hot deserts, the Sahara, Australia or more recently in the Sultanate of Oman. These areas are dry places, suitable for meteorite conservation and concentration. Most of the lunar meteorites were discovered during expeditions financed by the American (ANSMET), Japanese and European governments (EUROMET). For example, NWA 10782 was discovered in 2015 in the Almabas region near the Moroccan-Algerian border on the desert plateau. The first meteorite recognized as coming from the Moon was found on July 18, 1982 by a team of American scientists. But, it is actually a Japanese team that found the first one on November 20, 1969, however its Lunar origin was not recognized until after 1982!
Dr. Luc Labenne
Member of the Meteoritical Society