Nakhlite

Nakhla meteorite's two sides and its inner surfaces after breaking it in 1998

Nakhlites are a group of Martian meteorites, named after the first one, Nakhla meteorite.

Nakhlites are igneous rocks that are rich in augite and were formed from basaltic magma about 1.3 billion years ago. They contain augite and olivine crystals. Their crystallization ages, compared to a crater count chronology of different regions on Mars, suggest the nakhlites formed on the large volcanic construct of either Tharsis, Elysium, or Syrtis Major Planum.^[1]

It has been shown that the nakhlites were suffused with liquid water around 620 million years ago and that they were ejected from Mars around 10.75 million years ago by an asteroid impact. They fell to Earth within the last 10,000 years.^[1]

Samples

Lafayette

NWA 998

Y000593

The following samples of nakhlites are known.

• Nakhla meteorite (about 40 samples, total estimated weight 10 kilograms (22 lb)), vicinity of Nakhla, Abu Hommos district, Alexandria Governorate, Egypt, 1911
• Governador Valadares meteorite ^[2]
• Lafayette meteorite, 800g, before 1931 ^[3]
• NWA817, 104g, Morocco, 2000 ^[4]
• NWA998, 456g, Morocco, 2001 ^[5]
• Y000593 (Yamato 593), 13.7 kilograms (30 lb)^{[6][7][8][9][10]}
• Y000749, 1.28 kilograms (2.8 lb) ^[9][11]
• Y000802, 22g ^[9]
• MIL 03346 Miller Range, Antarctica^[12]
• MIL 090030, MIL 090032, and MIL 090136, Miller Range, Antarctica^[12]

See also

• Glossary of meteoritics

References

1. Treiman, A.H., "The nakhlite meteorites: Augite-rich igneous rocks from Mars" - (PDF) Chemie der Erde 65, p. 203-270, (2005). URL accessed July 30, 2011.
2. "Mineralogy of nakhlite Martian meteorites: Implications for their relative burial depths ", Mikouchi, T.; McKay, Gordon; Miyamoto, M., 2006, NASA Technical Reports Server
3. "Lafayette - 800 grams Nakhlite", Martian Meteorite Compendium, C. Mayer, 2012
4. NWA 817 – 104 grams Nakhlite
5. NWA 998 – 456 grams Nakhlite
6. Webster, Guy (February 27, 2014). "NASA Scientists Find Evidence of Water in Meteorite, Reviving Debate Over Life on Mars". NASA. Retrieved February 27, 2014.
7. White, Lauren M.; Gibson, Everett K.; Thomnas-Keprta, Kathie L.; Clemett, Simon J.; McKay, David (February 19, 2014). "Putative Indigenous Carbon-Bearing Alteration Features in Martian Meteorite Yamato 000593". Astrobiology 14 (2): 170–181. doi:10.1089/ast.2011.0733. Retrieved February 27, 2014.
8. Gannon, Megan (February 28, 2014). "Mars Meteorite with Odd 'Tunnels' & 'Spheres' Revives Debate Over Ancient Martian Life". Space.com. Retrieved February 28, 2014.
9. http://curator.jsc.nasa.gov/antmet/mmc/Y000593.pdf
10. Imae N., Okazaki R., Kojima H. and Nagao K. (2002a) The first Nakhlite from Antarctica (abs#1483). Lunar Planet. Sci. XXXIII. Lunar Planetary Institute, Houston
11. Imae N., Ikeda Y., Shinoda K., Kojima H. and Iwata N. (2002c) Two Nakhlites from Antarctica: Y000593 and Y000749 (abs). Antarctic Meteorites XXVII, 45-47. Nat. Inst. Polar Res., Tokyo