NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Morphological Evidence for an Exclusively Inorganic Origin for Magnetite in Martian Meteorite ALH84001The origin of magnetite crystals in Martian Meteorite ALH84001 is the focus of a debate about the possibility of past (and present) life on Mars. McKay et al. originally suggested that some of the magnetite crystals associated with carbonate globules in Martian Meteorite ALH84001 are biogenic in ori-gin, because they are single magnetic domain, free of crystalline defects, chemically pure, and coexist with other metastable phases in apparent disequilibrium. Thomas-Keprta et al. reported that a subpopulation of magnetite crystals (approx. 25%) associated with carbonate globules in ALH84001 and magnetite crystals produced by magnetotactic bacterial strain MV-1 have similar morphologies with crystal elongation along the [111] crystallographic axis that they describe as "truncated hexa-octahedral" ([111-THO]) magnetite. Along with several other properties, the [111]-THO morphology has been proposed to constitute a biomarker (i.e., formed only in biogenic processes), so that the presence of [111]-THO magnetite in ALH84001 may be evidence for past life on Mars.
Document ID
20030111243
Document Type
Conference Paper
Authors
Golden, D. C. (Hernandez Engineering, Inc. Houston, TX, United States)
Ming, D. W. (NASA Johnson Space Center Houston, TX, United States)
Morris, R. V. (NASA Johnson Space Center Houston, TX, United States)
Brearley, A. J. (New Mexico Univ. Albuquerque, NM, United States)
Lauer, H. V., Jr. (Lockheed Martin Corp. Houston, TX, United States)
Treiman, A. (Lunar and Planetary Inst. Houston, TX, United States)
Zolensky, M. E. (NASA Johnson Space Center Houston, TX, United States)
Schwandt, C. S. (Lockheed Martin Corp. Houston, TX, United States)
Lofgren, G. E. (NASA Johnson Space Center Houston, TX, United States)
McKay, G. A. (NASA Johnson Space Center Houston, TX, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2003
Publication Information
Publication: Lunar and Planetary Science XXXIV
Subject Category
Lunar and Planetary Science and Exploration
Distribution Limits
Public
Copyright
Public Use Permitted.

Related Records

IDRelationTitle20030110578Analytic PrimaryLunar and Planetary Science XXXIV
Document Inquiry