Mineralized biosignatures in ALH-77005 Shergottite - Clues to Martian Life?
| Autor: | Szaniszló Bérczi, Ildikó Gyollai, Arnold Gucsik, Elemér Pál-Molnár, Márta Polgári |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Martian
010504 meteorology & atmospheric sciences Astronomy Astronomy and Astrophysics QB1-991 010502 geochemistry & geophysics 01 natural sciences microbial mediation Astrobiology alh-77005 biogenic signatures iron oxidizing bacteria (feob) martian meteorite Space and Planetary Science shergottite ftir-atr Ftir atr 0105 earth and related environmental sciences |
| Zdroj: | Open Astronomy, Vol 28, Iss 1, Pp 32-39 (2019) |
| ISSN: | 2543-6376 |
| Popis: | The ALH-77005 Martian meteorite was found in Allan Hills on Antarctica during the Japanese National Institute of Polar Research (1977-1978) mission. One thin section sample was studied by optical microscopy for microtexture and by FTIR-ATR microscopy for interpretation of biogenic minerals and embedded organic materials. The geochemical data (biogenic elements, δ13C) of ALH-77005 meteorite from literature implementing recent results were compared to terrestrial geological samples. The ALH-77005 has poikilitic textures with coarse pyroxenes and brown olivines, and with recrystallized melt pocket. The coarse-grained minerals do not contain any alteration along the grain boundaries. Melt pocket and vicinity of opaque minerals contain biogenic signatures as filamentous, coccoidal forms of iron-oxidizing bacteria. The biosignatures were determined by 1) coccoidal, filamentous forms, 2) presence of embedded organic material, 3) presence of biogenic minerals, like ferrihydrite, goethite, and hematite. The other signatures for biogenicity of this meteorite are strong negative δ13C, enrichment of Fe, Mn, P, Zn in shock melt support scenario. This study proposes presence of microbial mediation on Mars. |
| Databáze: | OpenAIRE |
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