D. radiodurans cells after high-pressure impacts. Credit: PNAS Nexus
A recent study reveals that life could potentially persist through an asteroid impact event, a scenario more survivable than previously assumed for certain extremophiles; this life may not only survive, but it can also potentially travel between planets.
The study demonstrated that persistent Deinococcus radiodurans (a bacterium renowned for its extreme resistance to radiation and DNA damage) can endure the force(s) of an impact (asteroidal) without being destroyed and therefore may be capable of transporting life from one planet to another naturally, supporting lithopanspermia (natural interplanetary transfer of life via rocks).
The researchers recreated the impact forces of an asteroid impacting Mars resulting in rock debris being thrown into space by using a gas gun to drive a steel flyer plate at a 20° angle into a target assembly, slamming two steel plates together that contained D. radiodurans cells sandwiched in-between (between front and back plates, with cells filtered onto polycarbonate membranes facing inward and supported by soaked glass fiber filters for a moist environment) to generate transient high-pressure shocks (up to ~3 GPa). Most of the D. radiodurans cells survived in the lower-pressure impacts (1.4-1.9 GPa), with an estimated ~95% of them surviving at 1.4 GPa and ~86% at 1.9 GPa; while at 2.4 GPa, approximately 60% survived. Below 10% survival occurred only at the highest pressure used in testing (~2.9 GPa).
Furthermore, the D. radiodurans cells that survived were actively mounting stress responses, including up-regulation of DNA repair, recombination, and replication genes (e.g., recA, ddrA, recN, uvrB, ung), ion transporters, and defence mechanisms, rather than just surviving. This supports the theory of lithopanspermia, that life can travel between planets (inside a rock or similar material) without needing to be dispatched.
Life on Earth may be derived from outer space or be able to propagate life on other planets (in the future) without using spacecraft.
Additionally, these findings are also highly relevant to planetary protection efforts. As NASA and ESA prepare for future sample-return missions from Mars and asteroids to Earth, understanding the potential for microbes to survive and/or travel between planetary surfaces will be instrumental in preventing contamination to/from other celestial bodies and in ensuring that returned samples remain suitable for future study.
The discovery of life capable of surviving asteroid impacts is more than a fascinating observation. It provides a new insight and understanding of how resilient life can be. If microbes can survive travelling through space, then the solar system may be even more biologically connected than previously thought.
Reference:
Zhao, L., Perez‑Fernandez, C. A., DiRuggiero, J., & Ramesh, K. T. (2026). Extremophile survive the transient pressures associated with impact‑induced ejection from Mars. PNAS Nexus
https://academic.oup.com/pnasnexus/article/5/3/pgag018/8503064
