Tardigrades Shot Out of a Gun to Test Origin-of-Life Theory
mrpg writes:
Tardigrades Shot Out of a Gun to Test Origin-of-Life Theory:
[...] So, we've got enough plausible bits and pieces to cobble together a theory. Only problem is, can life actually survive slamming into another planet at the sorts of temperatures and speeds associated with meteorite impacts? This is where the tardigrades come in.
Testing Tardigrades
As scientists Alejandra Traspas and Mark J. Burchell write in Astrobiology: "The ability of tardigrades to survive impact shocks in the kilometer per second and gigapascal range was investigated." Tardigrades, it turns out, can only withstand a shock pressure of ~1.14 gigapascals. Above 2,000 miles per hour, or above 900 meters per second, even the tardigrade's legendary toughness fails it.This has implications for the types of scenarios in which panspermia could occur. Spores and microbes are hardier, surviving impacts of up to 5000 meters per second and pressures of 40 gigapascals or more. According to the authors, tardigrades have been tested for static loading of up to 7.5 gigapascal (and survived it), but no one has tested to see if they can survive the impact. The scientists write: "Accordingly, we have fired tardigrades at high speed in a gun onto sand targets, subjecting them to impact shocks and evaluating their survival."
Journal Reference:
Alejandra Traspas , Mark J. Burchell. Tardigrade Survival Limits in High-Speed Impacts [open], Astrobiology (DOI: 10.1089/ast.2020.2405)
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