Brown University | 2016 Apr 14
A new set of experiments sheds light on how much heat is created when ice is deformed, which could help scientists understand the possibility of a subsurface ocean on one of Jupiter’s moons.
[img3="A false color image shows Europa's surprising surface. The inset includes regions where crustal plates appear to have broken up and rafted to new positions.Jupiter’s moon Europa is under a constant gravitational assault. As it orbits, Europa’s icy surface heaves and falls with the pull of Jupiter’s gravity, creating enough heat, scientists think, to support a global ocean beneath the moon’s solid shell.
Credit: NASA/JPL-Caltech/Univ. of Arizona)"]https://news.brown.edu/files/styles/hor ... k=xpMhWcYV[/img3][hr][/hr]
Now, experiments by geoscientists from Brown and Columbia universities suggest that this process, called tidal dissipation, could create far more heat in Europa’s ice than scientists had previously assumed. The work could ultimately help researchers to better estimate the thickness of moon’s outer shell. ...
The largest Jovian moons—Io, Europa, Ganymede and Callisto—were first discovered by Galileo in the early 1600s. When NASA sent spacecraft to Jupiter in the 1970s and 1990s, those moons proved to be full of surprises.
“[Scientists] had expected to see cold, dead places, but right away they were blown away by their striking surfaces,” said Christine McCarthy, ... “There was clearly some sort of tectonic activity—things moving around and cracking. There were also places on Europa that look like melt-through or mushy ice.”
The only way to create enough heat for these active processes so far from the sun is through tidal dissipation. The effect, McCarthy says, is a bit like what happens when someone repeatedly bends a metal coat hanger. ...
Tidal Dissipation in Creeping Ice and the Thermal Evolution of Europa - Christine McCarthy, Reid F. Cooper
- Earth and Planetary Science Letters 443:185 (01 Jun 2016) DOI: 10.1016/j.epsl.2016.03.006