Did Life Hitch a Ride to Earth? Scientists Smashed the Living Crap Out of Microbes to Find Out

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https://gizmodo.com/did-life-hitch-a-ride-to-earth-scientists-smashed-the-living-crap-out-of-microbes-to-find-out-2000729073

The tiniest life forms are also among Earth’s toughest, from near-invincible tardigrades to extremophilic microbes that thrive near volcanoes and hydrothermal vents. But could some of these itsy-bitsy creatures survive a journey through space tucked inside an asteroid—and then take root on another world? A wild new experiment suggests the answer is yes.

In a PNAS Nexus study published today, Johns Hopkins University researchers discuss the results of a microbe-launching experiment to test the lithopanspermia hypothesis. This well-known theory dares to suggest that life arrived on this planet from elsewhere, in the form of microbes hitching rides aboard asteroids or comets. To test this theory, the astrobiologists behind the new study created an apparatus to replicate how much pressure and physical stress a microorganism would have to endure while riding on an asteroid long enough to reach another planet.

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Then again, the microbes in this particular experiment, Deinococcus radiodurans, may as well have been invincible. For their test, the researchers simulated the pressure of an asteroid strike and ejection from Mars by firing high-speed projectiles at the microbes, sandwiched between metal plates.

Here’s where things get wild. The projectiles hit the plates at speeds up to 300 miles per hour (483 kilometers per hour), which adds up to about 1 to 3 gigapascals of pressure. And from all of this, the only thing that “died” was the steel plates, which eventually fell apart from so much slamming.

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The study (full text) is at https://academic.oup.com/pnasnexus/article/5/3/pgag018/8503064?searchresult=1&login=false .