Can life move from Mars to Earth? Study says it’s possible

Scientists have long known that pieces of Mars have landed on Earth. Meteorites discovered in Antarctica and other remote regions carry chemical signatures proving they originated on the Red Planet. What has remained uncertain is whether any form of life could have survived the violent journey through space.

A team at Johns Hopkins University decided to focus on the most extreme part of that journey: the moment when an asteroid strikes Mars and blasts rocks off its surface at escape velocity. If microbes ever traveled between planets inside those rocks, they would first need to survive that explosive launch. The researchers designed an experiment to simulate those impact conditions in the laboratory, per an article by StudyFinds.

They chose one of the toughest known bacteria on Earth, *Deinococcus radiodurans*. Discovered in the 1950s in radiation-sterilized canned meat that still contained living microbes, this organism has since become famous for surviving intense radiation, extreme cold, dehydration, and even the vacuum of space. However, its ability to endure the immense pressure of a planetary impact had never been directly tested.

Using a high-powered gas gun system, the team fired a metal projectile into samples containing about one billion bacterial cells sandwiched between steel plates. The collisions lasted only microseconds but generated pressures of up to nearly 3 gigapascals—tens of thousands of times greater than normal atmospheric pressure. Computer models suggest that rocks ejected from Mars during real asteroid impacts experience pressures below 5 gigapascals, meaning the experiment closely reflected realistic conditions.

The results were striking. At lower pressures comparable to those required to launch rocks into space, about 95 percent of the bacteria survived. Even as pressure increased, survival rates remained significant, only dropping sharply at the highest levels tested. By comparison, ordinary bacteria such as *Escherichia coli* survive similar pressures at extremely low rates.

Microscopic analysis showed that many cells remained structurally intact after impact, while damaged cells exhibited ruptured membranes and internal disruption. Surviving bacteria activated genetic repair systems similar to those used when exposed to high radiation, suggesting they can recover from mechanical shock. Researchers believe the bacterium’s unusually thick cell envelope may help it withstand the rapid pressure changes during impact and release.

The findings support the long-debated lithopanspermia hypothesis—the idea that life can travel between planets inside rocks ejected by asteroid impacts. While the study does not prove that life has ever moved between Mars and Earth, it demonstrates that at least one extremely resilient organism could survive the launch phase of such a journey.

Martian meteorites have already made it to Earth. This research suggests that if microbial life ever existed on Mars, the possibility of it surviving the initial blast into space is no longer as unlikely as once thought.

By Khagan Isayev