Allan Hills 77005

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Allan Hills 77005
Meteorite ALH-77005
TypeAchondrite (unique)[1][2]
ClanMartian meteorite
Composition~55% olivine, ~35% pyroxene, ~8% maskelynite and ~2% opaques[3]
Shock stageS6[4]
Weathering gradeA[1]
RegionAllan Hills
Coordinates76°43′00″S 159°40′00″E / 76.71667°S 159.66667°E / -76.71667; 159.66667Coordinates: 76°43′00″S 159°40′00″E / 76.71667°S 159.66667°E / -76.71667; 159.66667[1]
Observed fallNo[1]
Found date29 December 1977 (Japanese National Institute of Polar Research mission)[5][6]
TKW482.5 g[1]
Related media on Wikimedia Commons

Allan Hills 77005 (also known as Allan Hills A77005, ALHA77005, ALH77005 and ALH-77005[1][5]) is a Martian meteorite that was found in the Allan Hills of Antarctica in 1977 by a Japanese National Institute of Polar Research mission team[7] and ANSMET.[8] Like other members of the group of SNCs (shergottite, nakhlite, chassignite), ALH-77005 is thought to be from Mars.[9]


On discovery, the mass of ALH-77005 was 482.5 g (1.064 lb). Initial geological examination determined that the meteorite was composed of ~55% olivine, ~35% pyroxene, ~8% maskelynite and ~2% opaques.[3]

In March 2019, researchers reported the possibility of biosignatures in this Martian meteorite based on its microtexture and morphology as detected with optical microscopy and FTIR-ATR microscopy, and on the detection of mineralized organic compounds,[5][7][10] suggesting that microbial life could have existed on the planet Mars.[7] More broadly, and as a result of their studies, the researchers suggest Solar System materials should be carefully studied to determine whether there may be signs of microbial forms within other space rocks as well.[7]

See also[edit]


  1. ^ a b c d e f Staff (31 March 2019). "Meteoritical Bulletin Database: Allan Hills 77005". Meteoritical Bulletin Database. Retrieved 4 April 2019.
  2. ^ McSween Jr, Harry Y.; et al. (1 November 1979). "Petrogenetic relationship between Allan Hills 77005 and other achondrites". Earth and Planetary Science Letters. 45 (2): 275–284. Bibcode:1979E&PSL..45..275M. doi:10.1016/0012-821X(79)90129-8.
  3. ^ a b Meyer, C - Martian Meteorite Compendium (2012). "ALH77005 - 482grams - Intermediate Lherzolitic Shergottite" (PDF). NASA. Retrieved 4 April 2019.
  4. ^ Allan Hills A77005. The Meteoritical Society. Accessed on April 8, 2019. Quote: The meteorite has been severely shocked, as is shown by the presence of maskelynite, undulose extinction in the pyroxene, and occasional areas of apparent shock melting.
  5. ^ a b c Gyollai, Ildikó; et al. (29 March 2019). "Mineralized biosignatures in ALH-77005 Shergottite - Clues to Martian Life?". Open Astronomy. 28 (1): 32–39. Bibcode:2019OAst...28...32G. doi:10.1515/astro-2019-0002.
  6. ^ Baalke, Ron. "The ALHA 77005 Meteorite". NASA. Retrieved 4 April 2019.
  7. ^ a b c d De Gruyter (4 April 2019). "Life on Mars? - A Martian meteorite discovered 40 years ago delivers fresh evidence that life once existed on Mars". EurekAlert!. Retrieved 4 April 2019.
  8. ^ Cassidy, William (2003). Meteorites, Ice, and Antarctica: A personal account. Cambridge: Cambridge University Press. pp. 28-29, 115, 335–337. ISBN 9780521258722.
  9. ^ Anderson, Paul Scott (7 April 2019). "New evidence for life in a Martian meteorite? - The discovery of fossilized microbes in Martian meteorites has been claimed before. Now scientists in Hungary add a new study of the ALH-77005 meteorite, with some intriguing new evidence". Earth & Sky. Retrieved 7 April 2019.
  10. ^ De Gruyter (4 April 2019). "Life on Mars?". Retrieved 5 April 2019.

Further reading[edit]

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