The mysterious lumps on Jupiter’s moon Io || Could it be because of Lava and frost?

Jupiter Moon Io

Jupiter has 79 moons (53 officially named and another 26 waiting for official names). Among them the fifth moon named Io is the is the most active volcanic body in our solar system. The cause of this intense volcanic activity is because of the gravitational forces of Jupiter and the nearby moons Europa and Ganymede. The age of Io is about 4.5 billion years and it is slightly bigger than our moon. 

The Volcanic activity on this moon was first discovered by NASA's Voyager missions (1979). Though the surface temperature of Io is about -130 degree Celsius its volcanoes can reach a whooping of 1600 degree Celsius. The surface of the moon Io is primarily composed of sulfur and sulfur dioxide. 

Dunes on Jupiter’s moon Io

The lava sliding under the frost (Io's surface) can produce extremely tall dunes or heaps which is mysterious.This discovery was first explained in Nature communications. Two decades back scientists reported that, other than volcanoes there are ridge like structures on the Io's surface but it was ignored because they thought the moon's atmosphere is way too thin to form dunes which require strong winds.

But recently stellar objects such as Pluto and comet 67P, which too have thin atmospheres, are found with dune like structures. We know the phenomenon where molten lava when encountering a water body, it causes an explosion of steam. Similar to this phenomena, when lava creeps under Io's frozen surface, sulfur dioxide gas is exploded out like jets, which could send grains of rock and other material flying to form dunes.

Based on this hypothesis, a similar experiment was conducted by the researchers which caused a bursting (70 kilometres per hour) of vapor that propelled grains of particles around it. Also, an image taken by NASA exposed highly reflective rays of material radiating outward over dunes in front of lava flows (dark area in the picture). Some of these dunes are about 30 meters high. 

Jani Radebaugh, a planetary scientist at Brigham Young University in Provo, Utah says, "I think a lot of [scientists] looked at those and thought, hey, these really could be dunes...But what’s exciting about it is that they’ve come up with a good physical mechanism to explain how it’s possible.”