New research conducted onboard the International Space Station (ISS) shows that microbes may survive a trip to Mars by hitching a ride on Mars-bound spacecraft. The experiments indicate that it may be possible for microbes to become the first terrestrial organisms to colonize the Red Planet.

With the help of astronauts working up in orbit onboard the ISS, researchers have published a total of three separate papers studying the possibility of microorganisms ending up on Mars. The three research papers entitled Survival of Bacillus Pumilus Spores for a Prolonged Period of Time in Real Space Conditions, Resistance of Bacterial Endospores to Outer Space and Survival of Rock-Colonizing Organisms after 1.5 years in Outer Space were all published in the online journal Astrobiology.

In order to study the possible outcomes of microbes surviving throughout extended periods of time in space, the researchers needed to conduct long term experiments in space. This is where the European Technology Exposure Facility (EuTEF) module on the ISS came in. Using the specialized module, scientists were able to expose various microorganisms to the rigors of space during prolonged periods of time.

The researchers were investigating the possibility of microbes from Earth beating humans to the punch and colonizing other planets. Such a scenario is a cause for concern since many scientists are still looking for evidence of life on other planets. Mars is one of the prime candidates for investigating evidence of extraterrestrial life. However, contamination from spacecraft-borne microbes may completely invalidate any attempts to search for evidence of life on Mars. To eliminate or prepare for the possibility of terrestrial organisms launching an all-out invasion on the Red Planet, researchers needed a concrete idea regarding the ability of these microbes to survive the long trip to Mars.

"After testing exposure to the simulated Mars environment, we wanted to see what would happen in real space, and EuTEF gave us the chance," said Kasthuri J. Venkateswaran, one of the co-authors of all three papers on the subject.  "To our surprise, some of the spores survived for 18 months." These surviving spores had higher concentrations of proteins associated with UV radiation resistance and, in fact, showed elevated UV resistance when revived and re-exposed on Earth.  Venkateswaran is a researcher from NASA's Biotechnology and Planetary Protection Group ath the Jet Propulsion Laboratory (JPL).

In particular, the researchers investigated the possibility of spore-forming bacteria surviving the trip to Mars. This type of bacteria raised concerns since the spores they produce are known to survive many sterilization techniques used on the ground. Moreover, spores produced by the bacteria Bacillus pumilus SAFR-032 have been observed to be resilient to the sterilization techniques used specifically to clean spacecraft. After exposing samples of the bacterial spores to a simulated Martian environment, the spores were able to survive up to 30 minutes. Normal spores are known to die after a mere 30 second exposure to similar conditions.

The results of these experiments will be used to plan future missions to Mars.

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Tags: Microbes Mars ISS