Genesis Rock

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The Genesis Rock

The Genesis Rock is a sample of Moon rock retrieved by Apollo 15 astronauts James Irwin and David Scott in 1971 during their second lunar EVA. It is currently stored at the Lunar Sample Laboratory Facility in Houston, Texas.

Chemical analysis of the Genesis Rock indicated it is an anorthosite, composed mostly of a type of plagioclase feldspar known as anorthite. The rock was formed in the early stages of the solar system, at least 4 billion years ago.[1] It was recovered in a crater of the Moon, near other rocks of its kind.

It was originally thought they had found a piece of the Moon's primordial crust, but later analysis initially showed that the rock was only 4.1 ± 0.1 billion years old, which is younger than the Moon itself; and was formed after the Moon's crust solidified. But it was still an extremely old sample, and was from the Pre-Nectarian. Dating of pyroxenes from other anorthosite samples gave a samarium-neodymium age of crystallization of 4.46 billion years.[2]

The solar system was formed only around 100 million years earlier.[3]

See also[edit]

Apollo 15 Genesis Rock replica at the U.S. Astronaut Hall of Fame


  1. ^ Apollo 15 samples overview Lunar and Planetary Institute
  2. ^ Norman, M. D., Borg, L. E., Nyquist, L. E., and Bogard, D. D. (2003) Chronology, geochemistry, and petrology of a ferroan noritic anorthosite clast from Descartes breccia 67215: Clues to the age, origin, structure, and impact history of the lunar crust, Meteoritics and Planetary Science, vol 38, p. 645-661 Summary
  3. ^ Chaikin, A., and T. Hanks. 1998. A man on the Moon : the voyages of the Apollo astronauts. Penguin Books, New York, N.Y.

External links[edit]