Horneck, Gerda; Stöffler, Dieter; Ott, Sieglinde; Hornemann, Ulrich; Cockell, Charles S.; Moeller, Ralf; Meyer, Cornelia; de Vera, Jean-Pierre; Fritz, Jörg; Schade, Sara and Artemieva, Natalia A.
|DOI (Digital Object Identifier) Link:||http://dx.doi.org/10.1089/ast.2007.0134|
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The scenario of lithopanspermia describes the viable transport of microorganisms via meteorites. To test the first step of lithopanspermia, i.e., the impact ejection from a planet, systematic shock recovery experiments within a pressure range observed in martian meteorites (5–50 GPa) were performed with dry layers of microorganisms (spores of Bacillus subtilis, cells of the endolithic cyanobacterium Chroococcidiopsis, and thalli and ascocarps of the lichen Xanthoria elegans) sandwiched between gabbro discs (martian analogue rock). Actual shock pressures were determined by refractive index measurements and Raman spectroscopy, and shock temperature profiles were calculated. Pressure-effect curves were constructed for survival of B. subtilis spores and Chroococcidiopsis cells from the number of colony-forming units, and for vitality of the photobiont and mycobiont of Xanthoria elegans from confocal laser scanning microscopy after live/dead staining (FUN-I). A vital launch window for the transport of rock-colonizing microorganisms from a Mars-like planet was inferred, which encompasses shock pressures in the range of 5 to about 40 GPa for the bacterial endospores and the lichens, and a more limited shock pressure range for the cyanobacterium (from 5–10 GPa). The results support concepts of viable impact ejections from Mars-like planets and the possibility of reseeding early Earth after asteroid cataclysms.
|Item Type:||Journal Article|
|Copyright Holders:||2008 Mary Ann Liebert Inc.|
|Academic Unit/Department:||Science > Physical Sciences
|Interdisciplinary Research Centre:||Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)|
|Depositing User:||Charles Cockell|
|Date Deposited:||26 Jan 2011 11:36|
|Last Modified:||18 Jan 2016 09:40|
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