MONDAY, 15 JUNE 2015Is it possible that these primitive organisms could exist on Mars? Rebecca Mickol, a PhD student at the Arkansas Centre for Space and Planetary Sciences, presented work in New Orleans this month demonstrating that four species of methanogens can survive the low-pressure conditions found in sub-surface liquid aquifers on Mars. This builds on her previous work that shows that two of these species can also survive the extreme Martian seasonal freeze-thaw cycles, providing support that methanogens might be able to survive the hostile Martian environment.
If methanogens are responsible for the methane detected on Mars the question remains as to whether they are indigenous Martian extra-terrestrials or interplanetary hitch-hikers from Earth? Despite rigorous sterilization Martian landers still contain a small amount of microbial contamination before being launched into space. It has previously been believed that these microbes would die from extreme temperatures and radiation exposure en-route. However, work carried out on the International Space Station has shown that some bacterial spores can survive for 18 months in the vacuum of space when sheltered from solar radiation in tiny pockets on the spacecraft’s surface. This suggests that it might be feasible that some microbial species may survive the long space voyage to Mars.
At present the source of the Martian methane remains a controversial topic. The ExoMars Trace Gas Orbiter planned to be launched by the European Space Agency in 2016 and India’s Mars mission that is currently in orbit aim to survey a much larger area than Curiosity and will hopefully yield a conclusive explanation.
Written by Holly Ironfield.
Rebecca Mikol will be presenting her work at the 2015 General Meeting of the American Society for Microbiology, being held May 30-June 2 in New Orleans.