Mars could support life in the shape of methanogens, one of the simplest and oldest microorganisms found on Earth, a new study claims.
Methanogens, microorganisms in the domain Archaea, use hydrogen as their energy source and carbon dioxide as their carbon source, to metabolise and produce methane, also known as natural gas.
Methanogens live in swamps and marshes, but can also be found in the gut of cattle, termites and other herbivores as well as in dead and decaying matter.
Methanogens are anaerobic, so they don't require oxygen. They don't require organic nutrients, either and are non-photosynthetic, indicating they could exist in sub-surface environments and therefore are ideal candidates for life on Mars.
Rebecca Mickol, a doctoral student in space and planetary sciences at the University of Arkansas in US, found that in the laboratory, four species of methanogens survived low-pressure conditions that simulated a subsurface liquid aquifer on Mars.
"These organisms are ideal candidates for life on Mars," Mickol said.
"All methanogen species displayed survival after exposure to low pressure, indicated by methane production in both original and transfer cultures following each experiment. This work represents a stepping-stone towards determining if methanogens can exist on Mars," said Mickol.
Mickol, who has previously found that two species of methanogens survived Martian freeze-thaw cycles, conducted both studies with Timothy Kral, professor of biological sciences in the Arkansas Centre for Space and Planetary Sciences and lead scientist on the project.
