NASA | JPL-Caltech | Cassini | 2017 Nov 06
Heat from friction could power hydrothermal activity on Saturn's moon Enceladus for billions of years if the moon has a highly porous core, according to a new modeling study by European and U.S. researchers working on NASA's Cassini mission.
The study, published today in the journal Nature Astronomy, helps resolve a question scientists have grappled with for a decade: Where does the energy to power the extraordinary geologic activity on Enceladus come from?
Cassini found that Enceladus sprays towering, geyser-like jets of water vapor and icy particles, including simple organics, from warm fractures near its south pole. Additional investigation revealed the moon has a global ocean beneath its icy crust, from which the jets are venting into space. Multiple lines of evidence from Cassini indicate that hydrothermal activity -- hot water interacting chemically with rock -- is taking place on the seafloor.
One of those lines was the detection of tiny rock grains inferred to be the product of hydrothermal chemistry taking place at temperatures of at least 194 degrees Fahrenheit (90 degrees Celsius). The amount of energy required to produce these temperatures is more than scientists think could be provided by decay of radioactive elements in the interior. ...
Heating Ocean Moon Enceladus for Billions of Years
ESA | Science & Technology | Cassini-Huygens | 2017 Nov 06
Powering Prolonged Hydrothermal Activity Inside Enceladus - Gaël Choblet et al
- Nature Astronomy (online 06 Nov 2017) DOI: 10.1038/s41550-017-0289-8