Search for Past Life on Mars: Possible Relic Biogenic Activity in Martian Meteorite ALH84001
10.1126/science.273.5277.924
Crossref journal-article
American Association for the Advancement of Science (AAAS)
Science (221)
Abstract

Fresh fracture surfaces of the martian meteorite ALH84001 contain abundant polycyclic aromatic hydrocarbons (PAHs). These fresh fracture surfaces also display carbonate globules. Contamination studies suggest that the PAHs are indigenous to the meteorite. High-resolution scanning and transmission electron microscopy study of surface textures and internal structures of selected carbonate globules show that the globules contain fine-grained, secondary phases of single-domain magnetite and iron sulfides. The carbonate globules are similar in texture and size to some terrestrial bacterially induced carbonate precipitates. Although inorganic formation is possible, formation of the globules by biogenic processes could explain many of the observed features, including the PAHs. The PAHs, the carbonate globules, and their associated secondary mineral phases and textures could thus be fossil remains of a past martian biota.

Bibliography

McKay, D. S., Gibson, E. K., Thomas-Keprta, K. L., Vali, H., Romanek, C. S., Clemett, S. J., Chillier, X. D. F., Maechling, C. R., & Zare, R. N. (1996). Search for Past Life on Mars: Possible Relic Biogenic Activity in Martian Meteorite ALH84001. Science, 273(5277), 924–930.

Authors 9
  1. David S. McKay (first)
  2. Everett K. Gibson (additional)
  3. Kathie L. Thomas-Keprta (additional)
  4. Hojatollah Vali (additional)
  5. Christopher S. Romanek (additional)
  6. Simon J. Clemett (additional)
  7. Xavier D. F. Chillier (additional)
  8. Claude R. Maechling (additional)
  9. Richard N. Zare (additional)
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  88. We thank L. P. Keller V. Yang C. Le R. A. Socki M. F. McKay M. S. Gibson and S. R. Keprta for assistance; and R. Score and M. Lindstrom for their help in sample selection and preparation. The guidance of J. W. Schopf at an early stage of this study is appreciated. We also thank G. Horuchi L. Hulse L. L. Darrow D. Pierson and personnel from Building 37. The work was supported in part by NASA's Planetary Materials Program (D.S.M. and R.N.Z.) and the Exobiology Program (D.S.M.). Additional support from NASA-JSC Center Director's Discretionary Program (E.K.G.) is recognized. C.S.R. and H.V. acknowledge support from the National Research Council. X.D.F.C. acknowledges support from the Swiss National Science Foundation.
Dates
Type When
Created 18 years, 9 months ago (Oct. 27, 2006, 2:30 p.m.)
Deposited 1 year ago (Aug. 7, 2024, 7:34 a.m.)
Indexed 4 days, 6 hours ago (Aug. 21, 2025, 1:30 p.m.)
Issued 29 years ago (Aug. 16, 1996)
Published 29 years ago (Aug. 16, 1996)
Published Print 29 years ago (Aug. 16, 1996)
Funders 0

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@article{McKay_1996, title={Search for Past Life on Mars: Possible Relic Biogenic Activity in Martian Meteorite ALH84001}, volume={273}, ISSN={1095-9203}, url={http://dx.doi.org/10.1126/science.273.5277.924}, DOI={10.1126/science.273.5277.924}, number={5277}, journal={Science}, publisher={American Association for the Advancement of Science (AAAS)}, author={McKay, David S. and Gibson, Everett K. and Thomas-Keprta, Kathie L. and Vali, Hojatollah and Romanek, Christopher S. and Clemett, Simon J. and Chillier, Xavier D. F. and Maechling, Claude R. and Zare, Richard N.}, year={1996}, month=aug, pages={924–930} }