¿ Astronomy Picture of the Day [1]Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2021 February 3 IFRAME: [2]https://www.youtube.com/embed/V0UBZh6Hf-s?rel=0 Found on the Moon: Candidate for Oldest Known Earth Rock Video Credit: [3]NASA, [4]Astromaterials 3D, [5]Erika Blumenfeld et al. Explanation: Was the oldest known rock on Earth found on the Moon? Quite possibly. The story opens with the [6]Apollo 14 lunar mission. Lunar sample [7]14321, a large rock found in [8]Cone crater by astronaut [9]Alan Shepard, when analyzed back on Earth, was found to have a fragment that was a much [10]better match to Earth rocks than other Moon rocks. Even more surprising, [11]that rock section has recently been dated back [12]4 billion years, [13]making it older, to within measurement uncertainty, than [14]any rock ever found on Earth. A leading hypothesis now holds that an ancient comet or [15]asteroid impact launched Earth rocks into the Solar System, some of which fell back to [16]the Moon, became mixed with heated lunar soil and other rocks, cooled, and re-fragmented. [17]The video features an internal [18]X-ray scan of [19]14321 showing multiple sections with markedly different chemistries. [20]Moon rocks will continue to be [21]studied to learn a more complete history of the [22]Moon, the Earth, and the [23]early Solar System. Friday marks the [24]50th Anniversary of the [25]Apollo 14 [26]landing on the Moon. Tomorrow's picture: open space __________________________________________________________________ [27]< | [28]Archive | [29]Submissions | [30]Index | [31]Search | [32]Calendar | [33]RSS | [34]Education | [35]About APOD | [36]Discuss | [37]> __________________________________________________________________ Authors & editors: [38]Robert Nemiroff ([39]MTU) & [40]Jerry Bonnell ([41]UMCP) NASA Official: Phillip Newman [42]Specific rights apply. [43]NASA Web Privacy Policy and Important Notices A service of: [44]ASD at [45]NASA / [46]GSFC & [47]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://www.youtube.com/embed/V0UBZh6Hf-s?rel=0 3. https://www.nasa.gov/ 4. https://ares.jsc.nasa.gov/astromaterials3d/ 5. https://ares.jsc.nasa.gov/astromaterials3d/project-team.htm 6. https://www.nasa.gov/mission_pages/apollo/apollo-14 7. https://ares.jsc.nasa.gov/astromaterials3d/sample-details.htm?sample=14321-1404 8. https://en.wikipedia.org/wiki/Cone_(crater) 9. https://www.nasa.gov/sites/default/files/atoms/files/shepard_alan.pdf 10. https://i.pinimg.com/originals/11/12/e1/1112e1c4d14fe99f59c4918658ce91d9.jpg 11. https://solarsystem.nasa.gov/system/internal_resources/details/original/3348_Lunar_sample.png 12. https://apod.nasa.gov/apod/ap140805.html 13. https://solarsystem.nasa.gov/news/820/earths-oldest-rock-found-on-the-moon/ 14. https://en.wikipedia.org/wiki/Oldest_dated_rocks 15. https://youtu.be/bU1QPtOZQZU 16. https://apod.nasa.gov/apod/ap160201.html 17. https://youtu.be/V0UBZh6Hf-s 18. https://science.nasa.gov/ems/11_xrays 19. https://en.wikipedia.org/wiki/Big_Bertha_(lunar_sample) 20. https://curator.jsc.nasa.gov/lunar/index.cfm 21. https://www.nasa.gov/image-feature/nasa-lends-moon-rock-for-oval-office-display/ 22. https://solarsystem.nasa.gov/moons/earths-moon/in-depth/ 23. https://solarsystem.nasa.gov/solar-system/our-solar-system/in-depth/#otp_formation 24. https://www.nasa.gov/feature/50-years-ago-two-months-until-apollo-14 25. https://www.nasa.gov/mission_pages/apollo/missions/apollo14.html 26. https://youtu.be/oZZe-xXx9_o?t=689 27. https://apod.nasa.gov/apod/ap210202.html 28. https://apod.nasa.gov/apod/archivepix.html 29. https://apod.nasa.gov/apod/lib/apsubmit2015.html 30. https://apod.nasa.gov/apod/lib/aptree.html 31. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 32. https://apod.nasa.gov/apod/calendar/allyears.html 33. https://apod.nasa.gov/apod.rss 34. https://apod.nasa.gov/apod/lib/edlinks.html 35. https://apod.nasa.gov/apod/lib/about_apod.html 36. http://asterisk.apod.com/discuss_apod.php?date=210203 37. https://apod.nasa.gov/apod/ap210204.html 38. http://www.phy.mtu.edu/faculty/Nemiroff.html 39. http://www.phy.mtu.edu/ 40. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 41. http://www.astro.umd.edu/ 42. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 43. https://www.nasa.gov/about/highlights/HP_Privacy.html 44. https://astrophysics.gsfc.nasa.gov/ 45. https://www.nasa.gov/ 46. https://www.nasa.gov/centers/goddard/ 47. http://www.mtu.edu/