Hydrogen spraying from cracks in the surface of Enceladus hints at the presence of a buried chemical ecosystem that could support life.
Researchers reported in 2015 that Enceladus’s icy crust overlies a global ocean, which is thought to be the source of plumes seen spewing from the moon. In October 2015, NASA’s Cassini spacecraft took its deepest dive through one of the watery plumes in search of molecular hydrogen. Hunter Waite and Christopher Glein at the Southwest Research Institute in San Antonio, Texas, and their colleagues studied Cassini’s data and conclude that hydrogen probably formed from reactions driven by geothermal processes at the interface between Enceladus’s buried ocean and its rocky core. Life on Earth’s seafloor thrives on similar chemistry, even in the absence of sunlight.
Possible missions to search for life on Enceladus are under discussion.