The background: NASA’s spacecraft Cassini flew by Enceladus and spotted icy geysers erupting from the planet’s surface, indicating a liquid ocean beneath the ice sheets and possible hydrothermal activity. It flew through the geysers, and detected carbon, hydrogen, and crucially methane, in the plumes. That’s a big deal because certain types of bacterial life can produce methane.
What they did: Study author Simon Rittman ran a number of simulations to see if Methanermococcus okinawensi, a methane-producing microbe that lives on hydrothermal vents, could survive in an environment like on Enceladus. They altered the acidity and chemical composition of the environment, changed the pressure, and changed temperatures. Since no one knows exactly what the world is like beneath Enceladus’ ice sheets, they had to approximate.
What they found: The bacteria survived almost everything they threw at it, including low levels of formaldehyde, which were detected on the moon. But high levels killed the bacteria.
Yes, but the methane on Enceladus could have come from natural processes, and doesn’t need bacteria to be explained. It's also unknown if the hydrothermal vents Methanermococcus needs to survive are present on the planet — it’s just a guess.
