Lichens can Survive in Space |
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Written by spacetravel.org
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Friday, 11 November 2005 23:24 |
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A European Space Agency experiment has revealed that lichens, which are made up of algae and fungi living in a symbiotic relationship, can live in space unprotected. Lichens are now the most complex life form known to have survived prolonged exposure to space.
On 31 May 2005, 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. The lid of the container opened once the capsule was in Earth orbit. The samples were then exposed to the vacuum of space, the Suns ultraviolet radiation, and temperatures ranging from -20°C to 20°C. The lid was resealed and the capsule returned to Earth almost 15 days later.
The lichens appeared to be in the same shape after the flight as before. In space, the lichens became dormant and did not metabolise, but they returned to their normal activity after returning to Earth. Their DNA did not seem to be damaged.
Lichens are commonly found on the surface of rocks on Earth, and can survive in extreme conditions, for example, on high mountains. They have a tough mineral coating that could shield them from ultraviolet rays, and they have already shown that they can withstand high levels of ultraviolet radiation on Earth. Because lichens are made from individual organisms layered on top of one another, it is possible that the ouer layers may protect the inner ones.
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