How Long Can Life Wait?

# Summary Microorganisms can survive in the harsh conditions of space far longer than previously thought, particularly when shielded from ultraviolet radiation, which poses the primary threat to microbial life in space. Research on radiation-resistant bacteria like *Deinococcus radiodurans* shows they can remain viable for decades or longer, with implications for contamination risks in Mars exploration and the potential for life to have naturally spread throughout the early Solar System. These findings suggest that Earth microbes may already be present on Mars aboard spacecraft, raising important questions about planetary protection protocols and the search for extraterrestrial life.