In the movies, humans often fear invaders from Mars. These days, scientists are more concerned about invaders to Mars, in the form of micro-organisms from Earth. <\/p>\n
Three recent scientific papers examined the risks of interplanetary exchange of organisms using research from the International Space Station. <\/p>\n
All three, Survival of Rock-Colonizing Organisms After 1.5 Years in Outer Space, Resistance of Bacterial Endospores to Outer Space for Planetary Protection Purposes and Survival of Bacillus Pumilus Spores for a Prolonged Period of Time in Real Space Conditions, have appeared in Astrobiology Journal. <\/p>\n
Organisms hitching a ride on a spacecraft have the potential to contaminate other celestial bodies, making it difficult for scientists to determine whether a life form existed on another planet or was introduced there by explorers. So its important to know what types of micro-organisms from Earth can survive on a spacecraft or landing vehicle. <\/p>\n
Currently, spacecraft landing on Mars or other planets where life might exist must meet requirements for a maximum allowable level of microbial life, or bioburden. These acceptable levels were based on studies of how various life forms survive exposure to the rigors associated with space travel. <\/p>\n
If you are able to reduce the numbers to acceptable levels, a proxy for cleanliness, the assumption is that the life forms will not survive under harsh space conditions, explained Kasthuri J. Venkateswaran, a researcher with the Biotechnology and Planetary Protection Group at NASA's Jet Propulsion Laboratory and a co-author on all three papers. <\/p>\n
That assumption may not hold up, though, as recent research has shown that some microbes are hardier than expected, and others may use various protective mechanisms to survive interplanetary flights. <\/p>\n
Spore-forming bacteria are of particular concern because spores can withstand certain sterilization procedures and may best be able to survive the harsh environments of outer space or planetary surfaces. <\/p>\n
Spores of Bacillus pumilus SAFR-032 have shown especially high resistance to techniques used to clean spacecraft, such as ultraviolet (UV) radiation and peroxide treatment. <\/p>\n
When researchers exposed this hardy organism to a simulated Mars environment that kills standard spores in 30 seconds, it survived 30 minutes. <\/p>\n
<\/p>\n
Here is the original post: <\/p>\n
Space News: Space station research shows that hardy little space travelers could colonize Mars<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" In the movies, humans often fear invaders from Mars. These days, scientists are more concerned about invaders to Mars, in the form of micro-organisms from Earth. Three recent scientific papers examined the risks of interplanetary exchange of organisms using research from the International Space Station. Continue reading