SCI AM By Lee Billings 3/5/2026
New insights into a tiny, tough microbe have huge implications for the search for life beyond EarthChalk up another victory for “Conan the Bacterium”—a rugged germ that fresh research suggests could conquer the solar system.
Better known as Deinococcus radiodurans, this microbe is arguably the toughest organism known to science. Past studies have shown it can endure extreme cold, intense radiation, harsh chemicals and profound dehydration—all evolutionary adaptations, perhaps, to what’s thought to be its natural home in the high, dry and sun-scorched deserts of northern Chile.
Now a new experiment from researchers at Johns Hopkins University shows this hardy “extremophile” can also survive the immense shocks and mechanical stresses associated with asteroid strikes on Mars.
D. radiodurans “is the closest thing we can get to what we think a Martian life-form might look like without having an alien in our lab,” says Lily Zhao, a doctoral student at Johns Hopkins University, who led the experiment. “And we tried to kill it, but we couldn’t.”
To do so, the researchers fired a high-speed projectile from a gas gun at colonies of D. radiodurans that were sandwiched between two steel plates. The bacteria could withstand split-second exposures to extreme pressures of up to three gigapascals (GPa). That’s 30 times greater than pressures at the deepest point in Earth’s oceans—and similar to the crushing blow of an asteroid cratering into Mars and blasting fragments into space.
K. T. Ramesh, an impact expert at Johns Hopkins, who supervised the work, was shocked by the results. “Our expectation was that most of them would die,” he says, because other types of microbes in previous high-pressure studies had survival rates of only about 1 percent or less. Instead nearly all the D. radiodurans microbes survived initial 1-GPa shots. Even at the highest pressures of 3 GPa, more than half survived. Subsequent analyses, guided by Johns Hopkins microbiologists Cesar A. Perez-Fernandez and Jocelyne DiRuggiero, showed that some of the microbes had perished from ruptured cell walls but also confirmed the survivors could repair their damaged DNA, regrow and reproduce.
More:
https://www.scientificamerican.com/article/life-on-mars-could-reach-earth-by-riding-asteroid-impact-debris-new-study/
