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Life forms survive space exposure

June 25, 2012
Courtesy of the European Space Agency
and World Science staff

New re­search on the In­terna­t­ional Space Sta­t­ion is help­ing to boost the­o­ries that life came from out­er space—and might help cre­ate bet­ter sun­creams.

In 2008 sci­en­tists sent a suitcase-sized pack­age the Space Sta­t­ion filled with or­gan­ic com­pounds and liv­ing or­gan­isms to test their re­ac­tion to out­er space. Some of the life forms sur­vived the trip just fi­ne.

An example of a lichen that was exposed to space conditions on the International Space Station for 18 months. Some lichens survived the ordeal and continued to grow in the laboratory. (Courtesy ESA)


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

“We are ex­plor­ing the lim­its of life,” said René Demets of the Eu­ro­pe­an Space Agen­cy, which over­saw the proj­ect, dubbed the Expose-E ex­pe­ri­ment.

Our at­mos­phere pro­tects life on Earth by ab­sorb­ing harm­ful ul­tra­vi­o­let rays and sta­bi­liz­ing tem­per­a­tures. In con­trast, the space sam­ples en­dured the full pow­er of the Sun’s rays. Though in­su­lat­ed some­what by the Space Sta­t­ion, they ex­perienced tem­per­a­tures chang­ing from mi­nus 12 to plus 40 de­grees Cel­si­us (10 to 104 de­grees Fahren­heit), over 200 times as they or­bited Earth.

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

Li­chen have prov­en to be tough cook­ies: back on Earth, some of the spe­cies brought to space con­tin­ue to grow nor­mal­ly. Dur­ing hard­ship, they “go in­to a dor­mant state wait­ing for bet­ter con­di­tions to ar­rive,” René ex­plained. The li­chen have at­tracted in­ter­est from cos­met­ic com­pa­nies. They can sur­vive the full pow­er of the Sun for 18 months, so know­ing more might lead to new in­gre­di­ents for sun­cream.

Liv­ing or­gan­isms sur­viv­ing in open space sup­ports the idea of “pansper­mia” – life spread­ing from one plan­et to an­oth­er, or even be­tween so­lar sys­tems. It seems pos­si­ble that or­gan­isms could col­o­nise plan­ets by hitch­ing rides on as­ter­oids. The agen­cy is prob­ing this the­o­ry fur­ther on fu­ture Sta­t­ion mis­sions with dif­fer­ent sam­ples.


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New research on the International Space Station is helping to boost theories that life came from outer space—and might help create better suncreams. In 2008 scientists sent a suitcase-sized package the Space Station filled with organic compounds and living organisms to test their reaction to outer space. Some of the life forms survived the trip just fine. When astronauts go on a spacewalk, hours are spent preparing protective suits to survive the hostile conditions. But no effort was made to protect the bacteria, seeds, lichen and algae attached to the outside of the Space Station. “We are exploring the limits of life,” said René Demets of the European Space Agency, which oversaw the project, dubbed the Expose-E experiment. Our atmosphere protects life on Earth by absorbing harmful ultraviolet rays and stabilizing temperatures. In contrast, the space samples endured the full power of the Sun’s rays. Though insulated somewhat by the Space Station, they experienced temperatures changing from minus 12 to plus 40 degrees Celsius (10 to 104 degrees Fahrenheit), over 200 times as they orbited Earth. The samples returned to Earth in 2009 and the results are now published in a special issue of the journal Astrobiology. Lichen have proven to be tough cookies: back on Earth, some of the species brought to space continue to grow normally. During hardship, they “go into a dormant state waiting for better conditions to arrive,” René explained. The lichen have attracted interest from cosmetic companies. They can survive the full power of the Sun for 18 months, so knowing more might lead to new ingredients for suncream. Living organisms surviving in open space supports the idea of “panspermia” – life spreading from one planet to another, or even between solar systems. It seems possible that organisms could colonise planets by hitching rides on asteroids. The agency is probing this theory further on future Station missions with different samples.