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Even In Space, Life Perseveres June 24, 2012

Posted by Metabiological in Beyond Earth.
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Life, once thought to be a delicate and fragile thing that needed protection and nuturing, is turning out to be an incredibly hardy beast.  We’ve found life in the harshest and most extreme environments on the planet from deep sea hydrothermal vents where a startling variety of organisms endure temperatures up to 450 degrees C to the ice sheets of the Antartic where microorganisms live within cracks in the glaciers.  Now we are learning that even the vacuum of space can’t stop life.

n 2008 scientists sent the suitcase-sized Expose-E experiment package to the Space Station filled with organic compounds and living organisms to test their reaction to outer space.

When astronauts venture on a spacewalk, hours are spent preparing protective suits to survive the hostile conditions. No effort was made to protect the bacteria, seeds, lichen and algae attached to the outside of the Space Station, however.

“We are exploring the limits of life,” explains ESA’s René Demets.

Our atmosphere does a wonderful job of protecting life on Earth by absorbing harmful UV rays and keeping temperatures relatively stable.

In contrast, the space samples endured the full power of the Sun’s rays. The samples were insulated somewhat by the Space Station but still had to cope with temperatures changing from -12ºC to +40ºC over 200 times as they orbited Earth.

The samples returned to Earth in 2009 and the results have now been published in a special issue of the journal Astrobiology.

Lichen have proven to be tough cookies — back on Earth, some species continue to grow normally.

Believe it or not this isn’t the first example of life enduring conditions outside the atmosphere.  Tardigrades (aka waterbears) along with surviving in seemingly every extreme environment on Earth have been known to tolerate vacuum conditions for up to ten days.

While mostly a curiosity at this point this kind of research could lead to potentially interesting breakthroughs.  One off the top of my head is a better understanding of how to grow and maintain food in space.  Despite the protections put in place space craft are not impervious to radiation from the sun.  As such in addition to the myriad of other obstacles growing food in space is limited by the potential damage inflicted on organisms by solar rays.  Figuring out which food sources, and lichen is apparantally capable of being used as a food source, are resistant is a necessary step.  Growing your own food would have the advantage of reducing the cost of lifting the necessary food into orbit and provide a safety margin on long journeys when the astronauts are several million kilometers away from the nearest supermarket.