Lichens as survivors in space and on Mars

Many lichens are able to live and photosynthesize under harsh conditions, characterized by low temperatures, aridity and high UV radiation fluxes. Some lichen species are even able to survive simulated and real space conditions. Many tests after space exposure on the satellite FOTON M3 and on the International Space Station have shown their capacity to maintain physiological and photosynthetic activity, and their capacity to germinate and grow after being exposed to space parameters. Further tests using simulated Martian atmospheres, temperatures, humidity profiles and UV radiation spectra and fluxes have shown maintenance of photosynthetic activity of Xanthoria elegans. Results from space and Mars simulation experiments on lichens such as X. elegans are valuable for determining the habitability of a planet and for the search for possible life-supporting habitats on planets like Mars.

► Lichens survive space simulation conditions. ► Lichens survive exposure to real space conditions in low Earth orbit. ► Lichens are active in Mars simulation conditions. ► Lichens are candidates to survive the first two scenarios of “Lithopanspermia”. ► Eukaryotic symbiotic systems can compete with prokaryotes’ resistance potential.