Plantwatch: the strange organism so tough it can survive in space

Lichen survived 18 months attached to outside of International Space Station and raises prospect life could exist on Mars

Lichens are strange organisms, a partnership between a fungus that offers shelter, water and minerals, and an alga or cyanobacterium that supplies food from their photosynthesis. And even though lichens tend to be modest to look at, they are so incredibly tough that some can even survive the harsh environment of space.

When lichens were attached to the outside of the International Space Station for 18 months they survived the vacuum of space, no water, extreme temperatures and the full onslaught of radiation and ultraviolet rays from the sun, and carried on photosynthesising.