ALH-77005, a Martian rock found in Antarctica, contains numerous mineralized "biosignatures," including filament structures and organic coconut material, according to a team of Hungarian scientists.
An artistic impression of habitable Mars. Image credit: Daein Ballard / CC BY-SA 3.0.
"Our work is important for a wide audience because it integrates planetary, terrestrial, biological, chemical and environmental sciences, and will be of great interest to many researchers in those fields," said Dr. Ildiko Gyollai, team leader and researcher at HAS. Research. Center for Astronomy and Earth Sciences in Budapest.
"The research will also be of interest to planetologists, experts in meteorites and astrobiology, as well as to researchers of the origin of life, and to the general public, as it offers an example of a novel aspect of microbial mediation in meteorites. of stone".
Thin section of ALH-77005: poikilitic texture of olivine with pyroxene cumroxene grains, the studied molten pocket (rectangle) composed mainly of olivine. Image credit: Gyollai. et al, doi: 10.1515 / astro-2019-0002.
The meteorite meteorite ALH-77005 was found partially embedded in the ice at the site of Allan Hills in the South Victoria Land during the mission of the National Polar Research Institute of Japan in 1977-1978.
It had a rounded shape and its surface was partially ablated and polished approximately by ice blown by the wind.
Its age is estimated at about 175 million years, with an exposure to cosmic rays of about 3 million years.
Thin section of ALH-77005 in plane polarized light: the area studied by FTIR spectroscopy is marked with a rectangle, where an alleged microbial-mediated alteration was observed. Image credit: Gyollai. et al, doi: 10.1515 / astro-2019-0002.
Dr. Gyollai and his co-authors badyzed a thin section of ALH-77005 by light microscopy and FTIR-ATR.
They were able to detect the presence of corallid and filamentous structures (probably built by microbes that oxidize iron); organic material; Biogenic minerals, such as ferrihydrite, goethite and hematite.
"The other signatures for the biogenicity of ALH-77005 are strong negative at δ13C, enrichment of iron, manganese, phosphorus, zinc in the shock support scenario," the researchers said.
"Our study proposes the presence of microbial mediation on Mars."
The team's article was published online in the magazine. Open astronomy.
Ildikó Gyollai et al. 2019. Mineralized Biosignatures in Shergottite ALH-77005 – Martian Life Tracks? Open astronomy 28 (1): 32-39; doi: 10.1515 / astro-2019-0002