Genesis Rock
{{short description|Rock retrieved from the Moon in 1971}}
Image:Apollo 15 Genesis Rock.jpg
Image:Genesis rock in situ AS15-90-12227.jpg, which was used for scale in the photos)]]
The Genesis Rock (sample 15415) is a sample of Moon rock retrieved by Apollo 15 astronauts James Irwin and David Scott in 1971 during the second lunar EVA, at Spur crater on Earth's Moon. With a mass of {{circa}} {{convert|270|g|gr|-2|abbr=off}},{{cite web|url=https://curator.jsc.nasa.gov/lunar/lsc/15415.pdf|title=15415 Ferroan Anorthosite |publisher=NASA|access-date=November 29, 2022}} it is currently stored at the Lunar Sample Laboratory Facility in Houston, Texas.
Rock
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.[http://www.lpi.usra.edu/expmoon/Apollo15/A15_sampact.html Apollo 15 samples overview] Lunar and Planetary Institute
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 had already solidified. Research has shown that the Genesis Rock is not the oldest sample recovered from the moon, with sample 14321 (retrieved during the Apollo 14 mission) surpassing it.{{Cite web |last=Association (USRA) |first=Universities Space Research |title=Earth's Oldest Rock Found on the Moon |url=https://solarsystem.nasa.gov/news/820/earths-oldest-rock-found-on-the-moon |access-date=2023-08-15 |website=NASA Solar System Exploration}} It is still an extremely old sample, formed during the Pre-Nectarian period of the Moon's history. Dating of pyroxenes from other lunar anorthosite samples gave a samarium–neodymium age of crystallization of 4.46 billion years.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 [http://www.psrd.hawaii.edu/April04/lunarAnorthosites.html Summary] Other research methods approximate the age of the rock to be between 4 and 5 billion years old.{{Cite journal |last1=Wasserburg |first1=G. J. |last2=Papanastassiou |first2=D. A. |date=1971-12-02 |title=Age of an Apollo 15 mare basalt; Lunar crust and mantle evolution |url=https://dx.doi.org/10.1016/0012-821X%2871%2990110-5 |journal=Earth and Planetary Science Letters |volume=13 |issue=1 |pages=97–104 |doi=10.1016/0012-821X(71)90110-5 |bibcode=1971E&PSL..13...97W |issn=0012-821X|url-access=subscription }}
See also
References
{{Reflist}}
External links
- [http://www.lpi.usra.edu/lunar/missions/apollo/apollo_15/ Lunar and Planetary Institute - Apollo 15]
- [https://web.archive.org/web/20120721151636/http://www-pao.ksc.nasa.gov/history/apollo/apollo-15/apollo-15.htm NASA - Apollo 15]
- [http://www.hq.nasa.gov/office/pao/History/alsj/a15/a15.spur.html Discovering the Genesis Rock] {{Webarchive|url=https://web.archive.org/web/20210125195637/http://www.hq.nasa.gov/office/pao/History/alsj/a15/a15.spur.html |date=2021-01-25 }} (From the Apollo Lunar Surface Journal, scroll down to 145:41:48.)
- Astronaut Scott examines the Genesis rock. ([http://www.hq.nasa.gov/office/pao/History/alsj/a15/ap15-S71-43477.jpg image] {{Webarchive|url=https://web.archive.org/web/20210801162838/https://www.hq.nasa.gov/office/pao/History/alsj/a15/ap15-S71-43477.jpg |date=2021-08-01 }})
- An [http://www.lpi.usra.edu/lunar/missions/apollo/apollo_15/samples/ overview] of the samples collected by Apollo 15. (The Genesis Rock is sample #15415 and is described but not listed by its number.)
{{Apollo program|state=collapsed}}