The Beresheet mission to the Moon and its crew of tiny tardigrades landed a bit violently, with a velocity of a few hundred meters per second. Okay, it crashed. Folks, a spacecraft with a crew of tardigrades crashed onto the Moon. 

Tardigrades, tiny extremophiles often seen in microscope imagery of pond water, are really hard to kill, and folks, including me, have wondered if the tardigrades might have survived this impact. One of these curious folks was Ph.D. student Alejandra Traspas who turned his curiosity into research and, I kid you not, placed well-fed tardigrades into hollow nylon bullets and fired them into sand several meters away. 

They found that while tardigrades could survive the bullet impacting at 900 meters per second, sudden jolts of just 1.14 gigapascals would kill them. This means that had they been able to decelerate through sand, they would have survived, but that moment when the spacecraft hit and crumpled, the shocks from that would have killed the critters. While I’m sad there probably isn’t a generation of tardigrades ready to spring to life on the Moon, this is probably for the best; we really don’t want to contaminate everything in the solar system with Earth life.

More Information

Hardy water bears survive bullet impacts—up to a point (Science)

“Tardigrade Survival Limits in High-Speed Impacts—Implications for Panspermia and Collection of Samples from Plumes Emitted by Ice Worlds,” Alejandra Traspas and Mark J. Burchell, 2021 May 11, Astrobiology