Paul Helfenstein: People work very hard and pay their taxes, and I hope we’re doing a good job of showing them that their money is buying something really exciting.

That’s astronomer Paul Helfenstein, who’s on the imaging team for NASA’s Cassini spacecraft. Helfenstein’s excited about certain geological movements on the planet Saturn’s icy moon Enceladus.

Paul Helfenstein: One of the things that we’ve just recently discovered is that the surface of Enceladus is undergoing a process that’s called ‘spreading,’ in which new material is being created on the surface and we can see actual tectonic motions of portions of the surface across the South Pole.

On Earth, spreading happens when magma bubbles up into rifts on the ocean floor and hardens into rock. But on the moon Enceladus, scientists think water beneath the moon’s surface rises up to form more ice.

Paul Helfenstein: Certainly the fact that we’re seeing a conveyor belt-type spreading of terrain is a much stronger indication now that water may be present, at least deep beneath the surface.

Helfenstein suggested that convective heat deep inside Enceladus could be enough to melt and form a subterranean ocean.

Paul Helfenstein: That’s very exciting to scientists and non-scientists alike, because it suggests the possibility that there may be a habitability zone, an area where life could have evolved.

Our thanks to:
Paul Helfenstein
Cornell University
Ithaca, NY