Photo courtesy University of Arkansas
A University of Arkansas research team has received a three-year grant worth $391,675 from the NASA Exobiology Program to study methanogens to see if they could survive on Mars, the university announced Monday.
Methanogens use hydrogen as their energy source and carbon dioxide as their carbon source, to metabolize 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.
“These are some of the oldest and most prominent organisms on our planet,” said Tim Kral, professor of biological sciences in the Arkansas Center for Space and Planetary Sciences and lead scientist on the project. “We use these as models for life on Mars. What this means is, we study them under Martian conditions to see if they could currently exist on Mars as a native life form. That’s what this proposal is about; it’s looking at the metabolism of methanogens under Martian conditions to see if they could possibly exist up there.”
In 2004, scientists discovered methane in the Martian atmosphere, and immediately the question of the source became an important one.
“When they made that discovery, we were really excited because you ask the question ‘What’s the source of that methane?’” Kral said. “One possibility would be methanogens.”
For this project, the team will place four different species of methanogens in an environmental simulation chamber housed in the Space Center’s W.M. Keck Laboratory. They will drop the pressure to six millibars, the surface pressure of Mars. For comparison, the surface pressure of Earth at sea level is about 1013 millibars. By decreasing pressure, the scientists can determine if and at what rate these anaerobic beings will grow at Martian pressures.
The team will also analyze how organisms behave under the extreme Martian temperatures and exposure to ultraviolet radiation. Scientists believe that life requires the presence of water. The average surface temperature for Mars in the middle latitudes is -50 degrees Celsius, well below the freezing temperature of pure water. However, salts and other compounds in the water can lower the freezing point to a temperature that would allow liquid water to be present for a short period of time in a given day on or slightly below the Martian surface.
Kral’s research team includes Dan Lessner, assistant professor of biological sciences and space and planetary sciences, Vincent Chevrier, research assistant professor from space and planetary sciences, Rick Ulrich, professor of chemical engineering, and graduate students Rebecca Mickol and Navita Sinha.