In addition, Taubner and her colleagues modeled the water-rock reactions likely occurring in Enceladus' interior. They found that such reactions are likely producing lots of H2 — enough to sustain methanogenic organisms such as M. okinawensis, if any exist on the Saturn satellite.
To be clear, study team members aren't claiming that Enceladus' methane is biological; after all, the substance can be produced geologically as well (by reactions between rock and hot water, in fact). But the new results could help inform the search for life on ocean moons in the solar system, Rittmann said.
"From an astronomical perspective, future missions to Enceladus or other icy moons should be equipped to be able to detect methanogenic biosignatures related to methanogens, like certain lipids or ratios of certain carbon isotopes," he said.
There are currently no Enceladus missions on the books of NASA or any other space agency. But both NASA and the European Space Agency (ESA) are developing missions to explore the icy ocean moons of Jupiter.
NASA's entry, called Europa Clipper, will assess the habitability of the buried ocean on the Jovian satellite Europa over the course of dozens of flybys. ESA's mission, called Jupiter Icy Moons Explorer (JUICE), will also study Europa, though it will focus more on Ganymede and, to a lesser extent, Callisto.
Europa Clipper and JUICE are both scheduled to launch in the 2020s. NASA is also working on a separate Europa lander mission, though that project remains a concept at the moment.
The new study was published February 27 in the journal Nature Communications.
Scientists have also spotted methane in the atmosphere of Mars, and they're not sure where the Red Planet's store of the stuff is coming from. But more information should be coming soon: The Trace Gas Orbiter, part of the European-Russian ExoMars exploration program, is scheduled to begin measuring and mapping Mars methane in mid-April.
Originally published on Space.com.
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