That implies hardy water bears may not withstand crash-landing on a new planet
After freezing Hypsibius dujardini tardigrades to put them in a state of suspended animation, Traspas Muiña and planetary scientist Mark Burchell of the University of Kent in England loaded the dormant water bears into nylon bullets. The researchers fired those bullets from a five-meter-long instrument called a two-stage light gas gun, which looks more like a cannon than a firearm. The machine launched tardigrades at different speeds, ranging from about 550 to 1,000 meters per second, into bags of sand meant to mimic the lunar surface.
Smashing into sand faster than about 825 meters per second, or about one gigapascal of shock pressure, proved lethal for the tardigrades. But even surviving water bears didn’t escape unscathed. After being placed in water, they took up to 36 hours to recover. Water bears that were frozen and thawed without being pelted into sand bounced back within nine hours.
These results suggest the Beresheet tardigrades probably didn’t survive their lunar landing, Traspas Muiña says. Likewise, space rocks flying around the solar system usually smash into planets and moons at thousands of meters per second — far too fast for tardigrades to survive. But splashing down in water might offer a softer landing, she says. “It’s hard for [animals like water bears] to survive panspermia in the solar system, but it could happen.”
