The Whole Surface of This Hellish Moon Is Covered in Lakes of Lava

Io, one of Jupiter’s moons, is the most volcanically active world in the Solar System. With approximately 400 active volcanoes, around 150 are erupting at any given time. This constant activity results in the spewing of lava and gas, making Io a significant volcanic excretion factory. The Juno probe, with its Jovian Infrared Auroral Mapper (JIRAM), has provided valuable insights into Io’s volatile nature.

According to astrophysicist Alessandro Mura of the National Institute for Astrophysics in Italy, JIRAM’s high-resolution infrared images have revealed that Io’s surface is covered by lava lakes contained within caldera-like features. Approximately 3% of the observed surface area is covered by these molten lava lakes.

Io’s dynamic orbit around Jupiter, coupled with the gravitational influence of other Galilean moons, generates heat that is released in the form of volcanism. This gravitational tug-of-war causes stress on Io’s interior, leading to the frequent eruptions.

Despite our understanding of the dynamics causing Io’s volcanic activity, much remains unknown about how the volcanism manifests on its surface. However, the Juno probe’s recent close flybys of Io have provided unprecedented details, revealing sulfurous volcanic plumes and lava lakes shimmering on the surface.

Scientists have analyzed these data, particularly the infrared observations captured by JIRAM, and have observed lava lakes with a ring of exposed liquid lava around the edges and a hardening crust in the center. This pattern is reminiscent of Hawaiian lava lakes, with the walls likely being hundreds of meters high.

This observation suggests that the lava enters the lava lakes from a magma reservoir below the surface and drains out the same way, causing the lakes to rise and fall. As the lava crust moves up and down, it breaks against the walls of the lake, forming the typical lava ring seen in Hawaiian lava lakes.

This new information on Io’s volcanic processes is significant, as it adds to our understanding of how this complex and dynamic moon functions. Juno’s JIRAM instrument is proving to be an invaluable tool in this regard, especially in mapping Io’s previously unexplored north and south poles. The research has been published in Nature Communications.

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