An effective internal heating mechanism might be helping Enceladus to maintain its subsurface liquid ocean for billions of years.

Cassini spacecraft did a historical voyage around Saturn planet from 2004 to 2017. The spacecraft made an observation of the geological activity on Saturn’s sixth largest moon, Enceladus.

Cassini found that the frigid world has a vast global ocean lurking beneath its thick, icy shell. Besides that, it also found scores of geysers erupting from giant fissures in its surface. Thus, blasting plumes of water ice, organic molecules and other material into space at speeds of over 800 miles per hour.

Enceladus is only about 314 miles (505 kilometers) wide. So, because of its tiny size and thin icy crust, the moon should have been frozen solid by now.

This diagram reveals a cross-section of Saturn’s frigid moon Enceladus. Thus, showing how sources from the inside out may heat the moon. Credit: Surface: NASA/JPL-Caltech/Space Science Institute; interior: LPG-CNRS/U. Nantes/U. Angers. Graphic composition: ESA


The moon’s neighbor, Mimas, seems to be completely frozen and dead, but why not Enceladus?

paper published days ago in Nature Astronomy, explains why Enceladus is still active.

In the study, researchers presented the first computer model of Enceladus. Thus, replicating all of the moon’s fundamental characteristics as seen by Cassin.

“Where Enceladus gets the sustained power to remain active has always been a bit of a mystery,” says lead author Gaël Choblet from the University of Nantes in France in a press release, “but we’ve now considered in greater detail how the structure and composition of the moon’s rocky core could play a key role in generating the necessary energy.”

According to a new study, tidal friction could generate enough heat to power hydrothermal activity inside Saturn’s ocean moon Enceladus for billions of years.

This heat could help provide the kinds of conditions required for life to develop. So, the new study is working in favor of the moon as a potentially habitable world.

One possible source of this power is tidal heating. Here on Earth, the gravitational pull of the moon and sun causes tides. Whereas on the Enceladus, Saturn is the one that causes tidal forces, strong enough to significantly flex and heat its ice and rock.

Researchers also suggest that this ocean keeps warm because of Saturn’s tidal effects on the core of Enceladus. Energy from the hot, rocky core transfers to the water, heating it to at least 194 degrees Fahrenheit (90 Celsius).

This causes the water to well upward and outward, which creates hotspots on Enceladus’ ocean floor. The researchers’ simulation showed that one of these seafloor hotspots alone was capable of releasing about five gigawatts of energy.

So, the new model can explain the ocean of Enceladus as well as the activity seen at its south pole.

Thumbnail Image: Jets of water venting from the surface of Saturn’s moon Enceladus. Credit: Mark Garlick Getty Images