Lake of lava "smooth as glass" discovered on Jupiter's moon Io

NASA's Juno spacecraft found Io’s surface is as smooth as glass, just like volcanically created obsidian glass

By Matthew Rozsa

Staff Writer

Published April 23, 2024 5:40AM (EDT)

Jupiter (Getty Images/martin_adams2000)
Jupiter (Getty Images/martin_adams2000)

Loki Patera might sound like the name of a Norse god's heavy metal band, but it is actually a lake made of lava located on one of Jupiter's moons, Io. On Sunday NASA scientists released a new animation of Loki Patera's activities, revealing that the 127-mile-long (200 kilometers) natural feature seems to have a shimmering, reflective surface. In other words, the lava lake has cooled so much that it appears to be as smooth as glass.

The scientists ascertained this from data compiled by the Juno spacecraft, which made extremely close flybys of Io in December 2023 and February 2024. By approaching 930 miles (1,500 kilometers) the Jovian moon's surface, the researchers obtained close-up images of the celestial body's northern latitudes.

“Io is simply littered with volcanoes, and we caught a few of them in action,” Juno’s principal investigator Scott Bolton said during a news conference at the European Geophysical Union General Assembly in Vienna. “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.”

While illustrating Loki Patera was certainly important work, it is not the primary mission of the Juno spacecraft. One of its chief objectives is to determine whether Io contains enough water to support extraterrestrial life, which the researchers are doing by measuring for hydrogen and oxygen atoms (which comprise water) during its close encounters with Io's atmosphere.

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