Lichen back from space

These lichen samples were shown to the public at the COSPAR 2010 Meeting (www.cospar2010.org) this summer in Bremen, Germany. The lichen has an interesting history of traveling. In June 2005, it was send into space with BIOPAN (‘biological pan’) mounted externally to a Russian re-entry capsule. BIOPAN is a multi-user facility, which can be opened in space by telecommand to expose biological samples to the “local” conditions.

The lichen samples in the picture were exposed to the full spectrum of solar light including UV, cosmic rays, space vacuum, microgravity and extreme temperatures. Their BIOPAN container was closed and hermetically sealed during re-entry and return to Earth.

The lichens survived their exposure to space conditions during a two-week flight and resumed their metabolism on Earth. Although lichens live and thrive in harsh planetary environments such as desert rocks in Nevada, their space survival is a surprise. In the past, some scientist (and science fiction authors) have argued that lichens and other organisms might arrived on Earth via “space flight.” The current findings give more credit to such possibilities. But what natural system achieves the critical protection for organisms to enter the atmosphere from outer space and reach Earth's surface intact?