"Get your facts first, and then you can distort them as much as you please." (Mark Twain)
Friday, November 11, 2005
Lichens can survive unprotected in the harsh conditions of space, a European Space Agency experiment discovers.
The organisms are a composite of algae and fungi. They are commonly found on the surface of rocks on Earth and can survive in extreme conditions such as high mountains latitudes. Lichens are the most complex form of life now known to have survived prolonged exposure to space.
In an experiment led by Leopoldo Sancho from the Complutense University of Madrid, two species of lichen – Rhizocarpon geographicum and Xanthoria elegans – were sealed in a capsule and launched on a Russian Soyuz rocket on 31 May 2005.
Once in Earth orbit, the lid of the container opened and the samples were exposed to the space environment for nearly 15 days before the lid resealed and the capsule returned to Earth.
The lichens were subjected to the vacuum of space and to temperatures ranging from -20°C on the night side of the Earth, to 20°C on the sunlit side. They were also exposed to glaring ultraviolet radiation of the Sun.
“To our big surprise, everything went fine after the flight,” says Rene Demets, ESA’s project scientist for the Foton project. “The lichens were in exactly the same shape as before flight....”
The experiment adds weight to the theory of panspermia – that life could somehow be transported between planets, perhaps by hitching a ride on an asteroid. It also indicates that organisms similar to lichens might be able to survive on the surface of Mars – at least during the planet's summer.
And, in case you were wondering, "panspermia" is my new favorite word. It would also make an excellent band name.