Asteroid impacts may catapult life from one planet to another, as new research from Johns Hopkins University suggests that hardy bacteria can survive both the violent ejection from a planet and the journey through space.
In a recent paper published in PNAS Nexus, the Johns Hopkins team determined that bacteria can survive not only the intense pressure of an asteroid impact but also the harsh conditions of space. This has major implications for the precautions future space missions will need to take to avoid contaminating other planets with foreign life.
Moving Life From Planet to Planet
“Life might actually survive being ejected from one planet and moving to another,” said senior author K.T. Ramesh. “This is a really big deal that changes the way you think about the question of how life begins and how life began on Earth.”
Space is a violent place, as evidenced by the scars covering most bodies in our solar system. Some of the areas researchers are most interested in investigating on Mars with robotic rovers are the result of ancient impacts, such as Jezero Crater. In a dry riverbed within that crater, the Perseverance Mars rover collected a sample of organic material in 2024 that may represent one of the most significant signs yet of possible life on the Red Planet.
The Johns Hopkins team is investigating the possibility that such strikes could transport living organisms into space, riding on material ejected during an impact—a theory known as lithopanspermia. Meteorites originating on Mars have been discovered on Earth, demonstrating that material can travel from one planet to another. The key question, however, is whether any life could survive the journey.
Can Life Survive Impact?
The Johns Hopkins team was not the first to test this hypothesis, but earlier work was inconclusive. Additionally, those tests focused on common Earth organisms rather than extremophiles that would be more likely to survive on less hospitable planets. For a more realistic evaluation of the lithopanspermia hypothesis, the team developed a method to replicate the pressures involved in an ejection event and focused on a single extremophile: Deinococcus radiodurans.
Native to Chile’s high deserts, Deinococcus radiodurans possesses several traits that the team suspected would make it resilient to space travel. Among these are its tolerance for extreme cold and radiation. Additionally, the microorganism is protected by a thick, self-repairing outer structure.
“We do not yet know if there is life on Mars, but if there is, it is likely to have similar abilities,” Ramesh said.
The impact test involved placing the microbe between two metal plates and firing a projectile at it from a gas gun at 300 mph. Pressures experienced during the impact equaled ten to thirty times those at the bottom of the Mariana Trench, the deepest point in Earth’s oceans. The team found the microorganism remarkably resilient, detecting ruptured membranes and internal damage only at the highest impact levels. In fact, the steel plates broke before the bacteria did.
“We expected it to be dead at that first pressure,” said lead author Lily Zhao. “We started shooting it faster and faster. We kept trying to kill it, but it was really hard to kill.”
Comparing the Results
While the microorganism exceeded researchers’ expectations, asteroid impacts on Mars could be even more powerful than the forces simulated in the laboratory tests. Extremely powerful pressures are measured in gigapascals. The projectile striking the steel plates produced pressures ranging from one to three gigapascals. The higher end of that range was previously believed to be too extreme for life to survive. However, fragments ejected during an asteroid impact may experience pressures approaching five gigapascals.
“We have shown that it is possible for life to survive large-scale impact and ejection,” Zhao said. “What that means is that life can potentially move between planets. Maybe we’re Martians!”
The team says their research suggests future space missions will need to be even more cautious than previously estimated to avoid contaminating one planet with life from another, given how resilient extremophiles may be.
“We might need to be very careful about which planets we visit,” Ramesh added.
To follow up on the relationship between life and space impacts, the team is now investigating whether repeated asteroid impacts might produce even hardier bacterial populations, and whether other organisms—such as fungi—may also be able to withstand impact conditions.
The paper, “Extremophile Survives the Transient Pressures Associated with Impact-Induced Ejection from Mars,” appeared in PNAS Nexus on March 3, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.