Saturn's small moon Enceladus sprays water from a hidden ocean into space. Two studies published on September 25 in Science Advances suggest that, if anything lives in that ocean, a spacecraft flying through the spray would have a good chance of noticing.
Its ocean sits under an icy shell, and jets near its south pole throw ocean water out as tiny ice grains. NASA's Cassini spacecraft flew through them and measured what they are made of.
Sorted grains
The first study, led by Frank Postberg of Freie Universität Berlin, used Cassini data. It shows that ocean droplets freeze slowly as they move up through cracks in the ice. While they freeze, salts and organic material separate and end up concentrated in different grains. That makes each grain easier to analyze.
A microbe that copes
In the second study, researchers grew a microbe that makes methane, called Methanothermococcus okinawensis, under conditions like those in the Enceladus ocean. It adapted even to low levels of carbon dioxide.
Postberg is careful about what this means. "While that doesn't mean that there is life on Saturn's moon, our first study shows that, in the event that there is, future space missions might have a good chance of finding traces," he says.
The studies do not find life. They show where to look and how.
