Enceladus is the most habitable place in the solar system after Earth

Saturn’s icy moon Enceladus is emerging as the most habitable spot beyond Earth in the Solar System for life as we know it. “It has liquid water, organic carbon, nitrogen [in the form of ammonia], and an energy source,” says Chris McKay, an astrobiologist at NASA’s Ames Research Center in Moffett Field, California. Besides Earth, he says, “there is no other environment in the Solar System where we can make all those claims.”

A new study suggests that the ocean of Enceladus makes contact with the moon’s rocky silicate core, which means that the water may soak up elements like sulfur and phosphorus that are important for life’s complex chemical reactions.

“That silicate provides potentially some of the materials necessary for life,” says Cornell University astronomer Jonathan Lunine, one of the study’s authors. “So it makes, in fact, the interior of Enceladus a very attractive potential place to look for life.”

Heat output from the south polar region of Saturn’s moon Enceladus is far greater than was previously thought possible, according to a new analysis of data collected by NASA’s Cassini spacecraft, published in the Journal of Geophysical Research on March 4. Data from Cassini’s composite infrared spectrometer of Enceladus’ south polar terrain, which is marked by linear fissures, indicate that the internal heat-generated power is about 15.8 gigawatts, approximately 2.6 times the power output of all the hot springs in the Yellowstone region, or comparable to 20 coal-fueled power stations.

The moon’s heat is more than an order of magnitude higher than scientists had anticipated, according to Carly Howett, the lead author of study, at Southwest Research Institute in Boulder, Colo., and a composite infrared spectrometer science team member.

Astrobiology – Follow the Plume: The Habitability of Enceladus

The astrobiological exploration of other worlds in our Solar System is moving from initial exploration to more focused astrobiology missions. In this context, we present the case that the plume of Enceladus currently represents the best astrobiology target in the Solar System. Analysis of the plume by the Cassini mission indicates that the steady plume derives from a subsurface liquid water reservoir that contains organic carbon, biologically available nitrogen, redox energy sources, and inorganic salts. Furthermore, samples from the plume jetting out into space are accessible to a low-cost flyby mission. No other world has such well-studied indications of habitable conditions. Thus, the science goals that would motivate an Enceladus mission are more advanced than for any other Solar System body. The goals of such a mission must go beyond further geophysical characterization, extending to the search for biomolecular evidence of life in the organic-rich plume

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