Mars

Imagine a massive asteroid hitting Mars so hard that it blasts chunks of rock into space - some of these rocks eventually land on Earth as meteorites. Scientists wanted to know: if there were tiny life forms (bacteria) living in those Martian rocks, could they survive the incredible shock of being launched into space? They took one of Earth's toughest bacteria, Deinococcus radiodurans (nicknamed "Conan the Bacterium"), and subjected it to the same crushing pressures that would occur during such an impact. Amazingly, most of the bacteria survived pressures that would instantly crush almost any other living thing. This suggests that life could potentially hitchhike between planets on rocks, surviving the violent journey through space.