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Moon rock
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Breccia sample returned from the Moon by Apollo 15 astronauts in 1971. This sample was found at Spur Crater at the foot of the Apennine range near the Mare Imbrium. It is composed of broken and shock-altered fragments that were fused together after an impact of a large object created the Imbrium Basin. (Top) Basalt and (bottom) breccia samples returned from the Moon by Apollo 15 astronauts in 1971.The dark basalt rock, collected near Hadley Rille on the edge of the Imbrium Basin (Mare Imbrium), is about 13 cm (5.1 inches) long and is representative of the mare lavas that filled the basin 3.3 billion years ago, several hundred million years after the impact that created Imbrium. Its numerous vesicles were formed from bubbles of gas present in the lava when it solidified.The breccia sample, which measures about 6 cm (2.4 inches) across, was found at Spur Crater at the foot of the Apennine range, part of the material pushed up by the Imbrium impact. Dating from the formation of Imbrium, it is composed of broken and shock-altered fragments fused together during the impact. Moon rock crystals
What do rocks collected during Apollo 11 reveal about the Moon and beyond?
Learn more about the Nice model of solar system evolution and how samples brought back from the Moon fit within it
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Moon rock

Also known as: lunar source rock
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Breccia sample returned from the Moon by Apollo 15 astronauts in 1971. This sample was found at Spur Crater at the foot of the Apennine range near the Mare Imbrium. It is composed of broken and shock-altered fragments that were fused together after an impact of a large object created the Imbrium Basin.
Breccia sample returned from the Moon by Apollo 15 astronauts in 1971. This sample was found at Spur Crater at the foot of the Apennine range near the Mare Imbrium. It is composed of broken and shock-altered fragments that were fused together after an impact of a large object created the Imbrium Basin.

Moon rocks are primarily igneous, meaning they formed from cooled lava, unlike Earth's common sedimentary rocks. The two main types are basalts, found in the maria (dark, smooth plains), and anorthosites, common in the highlands (lighter, rougher areas). Many rocks are also breccias, composed of fragments from impact events.1

Lunar soils are fine-grained materials derived from these rocks, altered by micrometeoroid bombardment and the Moon's harsh environment. They contain glassy particles and elements from the Sun (solar wind). Scientists have studied lunar samples from the Apollo missions, Soviet Luna missions, and meteorites found on Earth. These rocks offer insights into the Moon's formation and history, suggesting it formed from a giant impact with a Mars-sized body about 4.6 billion years ago.12

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
5 Britannica Sources
  1. Moon - General characteristics
  2. Moon - Main groupings
  3. Moon - Origin and evolution
  4. Moon - Return to the Moon
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