*** Welcome to piglix ***

Lunar rocks


Moon rock or lunar rock is rock that is found on the Earth's moon, or lunar material collected during the course of human exploration of the Moon.

Moon rocks on Earth come from three sources: those collected by the US Apollo manned lunar landings from 1969 to 1972; samples returned by three Soviet Luna unmanned probes in the 1970s; and rocks that were ejected naturally from the lunar surface by cratering events and subsequently fell to Earth as lunar meteorites. During the six Apollo landing missions, 2,415 samples weighing 380.96 kilograms (839.87 lb) were collected. Three Luna spacecraft returned with 326 grams (11.5 oz) of samples. More than 300 lunar meteorites representing more than 30 different meteorite fall events (none witnessed) have been collected on Earth, with a total mass of over 190 kilograms (420 lb). Some were discovered by scientific teams searching for meteorites in Antarctica (e.g. ANSMET), with most of the remainder having been discovered by collectors in the desert regions of northern Africa and Oman.

Rocks from the Moon have been measured by radiometric dating techniques. They range in age from about 3.16 billion years old for the basaltic samples derived from the lunar maria, up to about 4.44 billion years old for rocks derived from the highlands. Based on the age-dating technique of "crater counting," the youngest basaltic eruptions are believed to have occurred about 1.2 billion years ago, but scientists do not possess samples of these lavas. In contrast, the oldest ages of rocks from the Earth are between 3.8 and 4.28 billion years old.

Moon rocks fall into two main categories: those found in the lunar highlands (terrae), and those in the maria. The terrae consist dominantly of mafic plutonic rocks. Regolith breccias with similar protoliths are also common. Mare basalts come in three distinct series in direct relation to their titanium content: high-Ti basalts, low-Ti basalts, and Very Low-Ti (VLT) basalts.


...
Wikipedia

...