Ocean covers Saturn’s sixth-largest moon Enceladus

Now, NASA has plans for an Enceladus Life Finder mission, which would use a smaller orbiter than Cassini, which could go to the moon, then be able to sample the water geysers coming from the global ocean and examine them for life forms.

NASA’s Cassini Mission has found a global ocean beneath the surface of Enceladus, an icy moon of Saturn. Gravity data collected by Cassini during several close passes of Enceladus supported the alternate theory of a global ocean beneath the ice.

The scientists spent seven years analyzing images and data to study the mystery of the moon’s ocean. The fact that the moon has a wobbly orbit is also an indicator of liquid water because scientists say if it were solid, that the moon wouldn’t wobble as much as it has been observed to do.

For Carolyn Porco, Cassini imaging team lead at Space Science Institute in Boulder, Colorado, this work illustrates complexity and the many different parts of scientific investigation – the primary measurements were marked manually; the geometry is derived from accurate knowledge of spacecraft location, tracking Cassini’s radio signal and using its images to locate features on the satellites.

“This was a hard problem that required years of observations, and calculations involving a diverse collection of disciplines, but we are confident we finally got it right”, Peter Thomas, a Cassini imaging team member at Cornell University, and lead author of the paper, said in a release detailing the news. Because the icy moon is not completely spherical, and because it changes speeds during various portions of its orbit around Saturn, the giant planet discreetly rocks Enceladus back and forth as it rotates. The team plugged their best-fit value for the wobble into different models for how Enceladus might be arranged on the inside, including ones where the moon was frozen from surface to core.

“This exciting discovery expands the region of habitability for Enceladus from just a regional sea under the south pole to all of Enceladus”, said Tiscareno, a Cassini participating scientist at the SETI Institute, Mountain View, California, and a coauthor of the paper.

“This proves that there must be a global layer of liquid separating the surface from the core”, he added.

The global ocean on Enceladus is actually below its surface.

One question that remains to be answered is what mechanisms prevent Enceladus’ ocean from freezing. “Cassini has been exemplary in this regard”. More information is needed before they can arrive at a concrete answer.

A moon that is too close to its host planet would not be hospitable to life either because reflected light and radiation from the surface of the planet would make the conditions on the moon too hot.