NASA’s Juno has recently performed some extremely close flybys of Io, the innermost of the four Galilean moons of Jupiter. The natural satellite is the most geologically active body in the Solar System, featuring 400 active volcanoes. Members of the Juno team have used data from recent encounters to reconstruct some intriguing features on the surface of Io.
Meet Loki Patera, the largest volcanic depression on Io. It is an enormous lava lake. On Earth, it would be the 13th largest lake in the world. In the middle of the lake, there is an island rising from the surface. That in itself is extreme but it’s not even the weirdest feature of the lake.
Io is a volcanic hellscape but it has such a thin atmosphere that not even the lava can keep the place warm. The moon’s surface temperature is well below the freezing point of water – cold enough for the sulfur dioxide erupted in its volcanos to snow back down onto the moon. So the lake’s surface alternates between being liquid and being solid. And insights into the solid state came directly from Juno.
Unlike the way we often picture lava to solidify on Earth, the surface of Loki Patera is not a grizzled black rock. It is as smooth as glass, so more like obsidian, another volcanic mineral. And the whole surface of the planet might be equally smooth. It is certainly smoother than the other large moons of Jupiter with their cracked icy surfaces. However, there are some outlying features, quite literally in the case of the so-called Steeple Mountain.
“Io is simply littered with volcanoes, and we caught a few of them in action,” Juno’s principal investigator Scott Bolton said in a statement. “We also got some great close-ups and other data on a 200-kilometer-long (127-mile-long) lava lake called Loki Patera. There is amazing detail showing these crazy islands embedded in the middle of a potentially magma lake rimmed with hot lava. The specular reflection our instruments recorded of the lake suggests parts of Io’s surface are as smooth as glass, reminiscent of volcanically created obsidian glass on Earth.”
Juno’s mission has been extended significantly from the original plans as the spacecraft continues to do amazing work. The mission team has been able to get a bit more daring flying past the moon as well as closer to the north pole of Jupiter than ever before. The observations are solving long-held mysteries about the atmosphere of Jupiter and how its storms move and evolve.
Bolton presented these and other Juno results during a news conference at the European Geophysical Union General Assembly in Vienna.
Source Link: Enormous, Glassy Lava Lake On Jupiter’s Io Revealed By NASA In Incredible Animation