Bacteria have proven their ability to survive collisions with asteroids and during interplanetary travel

Interplanetary Microorganism Migration: Experimental Data

Scientists from Johns Hopkins University conducted the first laboratory “impact” on bacteria in history, simulating conditions of an asteroid hitting Mars. The results published in *PNAS Nexus* provide new evidence for the panspermia hypothesis—the theory that life can move between planets in the Solar System.

What Was Done
1. Modeling Impact Conditions

- Created a brief pressure up to 3 GPa (≈ 30,000 atmospheres), approximating those occurring when a large asteroid impacts Mars.

- Laboratory equipment could not withstand higher loads.

2. Selection of Microorganism

- *Deinococcus radiodurans* (also known as “Conan the Bacterium”) is one of the most radiation‑, vacuum‑, and temperature‑resistant organisms on Earth.

- Its ability to rapidly repair DNA damage makes it an ideal model for studying survival limits in space.

3. Experiment

- Cells were placed between steel plates and subjected to pulsed compression from a gas gun, mimicking shock waves from an asteroid impact.

- Survival was assessed at different pressures: 1.4 GPa, 2.4 GPa, and 3 GPa.

Key Results
Pressure (GPa) Surviving Bacteria Observational Effects
1.4 ≈ 100 % Cells retain normal morphology.
2.4 ≈ 60 % Membrane ruptures and internal damage; many cells remain viable.
3 Significant portion Some cells die, but most survive; equipment breaks before complete bacterial destruction.

*RNA analysis* and *electron microscopy* showed activation of repair genes and recovery of damage after shock loading.

What It Means
- Mechanical properties: Thick cell walls and repair systems protect against severe mechanical ruptures.

- Panspermia confirmed: Microorganisms can survive a Martian impact blast (pressure peaks up to 5 GPa) and subsequent interplanetary travel.

- Practical implication: Disinfection protocols for spacecraft must be strengthened to prevent accidental spread of Earth microbes within the Solar System.

Conclusion
The experiment demonstrated that even extreme shock conditions do not fully destroy highly resilient bacteria. This opens new prospects for understanding life's origins and raises an important question about the safety of interplanetary missions.