Tardigrades in space

Date posted: September 9, 2008
Posted in: Behind the Science | Science education | Space science
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Silly astronauts. Space travel is for tardigrades!

The world’s space agencies go to great lengths to protect human beings entering the deep frozen vaccuum of space.  The prevailing belief has been that nothing could survive the ultra-cold, oxygen-deprived and radiation-intense conditions beyond Earth’s atmosphere.

Enter tardigrades: oblong invertebrates about a millimeter in length that can visit space, return to Earth, and go on living as usual.

Lead author Ingemar Jönsson, an ecologist at Kristianstad University College, and his colleagues have published a paper in the September 9 issue of Current Biology, a Cell Press journal, showing that tardigrades, also called water-bears, survived all of the challenges of space when they orbited Earth aboard the FOTON-M3 spacecraft launched by the European Space Agency last fall.

Jönsson and his colleagues were most surprised at the “complete lack of effects on survival and reproduction after exposure to the extremely dehydrating conditions of space vacuum,” he wrote in an email. “This shows that tardigrades can maintain the integrity of their cells even under the most severely dry conditions.”

On Earth, water bears live among lichens and mosses which often dry up. They are known to rehydrate after years of dry dormancy, and go on with their lives. And apparently, the tiny creatures can also weather vacuum conditions, temperatures near absolute zero, and — to some extent — solar UV radiation more than 1,000 times the level on Earth’s surface.

On Earth, UV radiation has been linked with changes to a cell’s genetic material. So, while about 10 percent of the tardigrades even reproduced after intense UV exposure, Jönsson said more work remains to see what’s happening on the inside.

“What is needed now is research on the cellular and molecular changes taking place when tardigrades are exposed to extreme dehydration and radiation,” he said. “Then we may begin to understand more about the mechanisms behind the tolerances of tardigrades.”

Images and more information about the ever-hardy tardigrades can be found here. For more about Jönsson’s work, visit his research website. (Be sure to select English language at top, if applicable.)

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