Many experiments have shown that some prokaryotes can survive in space. More recently this work has been extended to lichens, some of which can also survive in space. Xanthoria elegans can survive in a simulated Mars environment and even maintain photosynthetic activity, at least for a few days. Unfortunately the water on Mars is likely to be too saline to support lichens, athough some halophilic micro-organisms could survive.

There is further discussion of experiments to test the possibility of lithopanspermia - the spread of life between planets on rocky meteorites - but these are so far inconclusive.