Saturn's moon Titan could harbor life, but only a tiny amount

Summary

Titan, Saturn's largest moon, is a strange, alien world. Covered in rivers and lakes of liquid methane, icy boulders and dunes of soot-like "sand," its topography has long fascinated scientists and invited speculation on whether lifeforms might lurk beneath the moon's thick, hazy atmosphere. An international team of researchers co-led by Antonin Affholder at the U of A Department of Ecology and Evolutionary Biology and Peter Higgins at Harvard University's Department of Earth and Planetary sciences set out to develop a realistic scenario of what life on Titan might look like if it does exist, where it is most likely to occur and how much of it might be present. "In our study, we focus on what makes Titan unique when compared to other icy moons: its plentiful organic content," said Affholder, who is a postdoctoral research associate. This composite image shows an infrared view of Titan from NASA's Cassini spacecraft, acquired during a high-altitude fly-by, 6,200 miles above the moon, on Nov. 13, 2015. The view features the parallel, dark, dune-filled regions named Fensal (to the north) and Aztlan (to the south). NASA/JPL/University of Arizona/University of Idaho Using bioenergetic modeling, the team found that Titan's subsurface ocean, estimated to be as deep as about 300 miles, may support lifeforms that consume organic material. Published in The Planetary Science Journal, their study concludes that while Titan could possibly harbor simple, microscopic life, it likely could support only a few pounds of biomass overall. Often described as "Earthlike on the surface, ocean world on the inside," Titan is the target for future exploration via NASA's Dragonfly mission. While much has been speculated about possible scenarios that could give rise to living organisms on Titan based on the moon's abundant organic chemistry, previous estimates have suffered from what Affholder considers an overly simplistic approach. "There has been this sense that because Titan has such abund...