By flying through the plumes of Saturn’s moons (Titan and Enceladus), NASA’s Cassini spacecraft discovered an abnormally high concentration of methane, as well as carbon dioxide and dihydrogen
Highlights:
It discovered methane in Titan’s and a liquid ocean with erupting plumes of gas and water on Enceladus.
An international research team used new statistical methods to determine whether methanogenesis, or microbe-produced methane, could explain the molecular hydrogen and methane.