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A graphic shows what a lava lake, called Loki Patera, may look like on the surface of Jupiter’s moon Io.
Close flybys of Io, one of Jupiter’s moons and the most volcanically active world in our solar system, have revealed a lava lake and a towering feature called “Steeple Mountain” on the moon’s alien surface.
NASA’s Juno spacecraft, which arrived to study Jupiter and its moons in 2016, flew within roughly 930 miles (1,500 kilometers) of the lava world’s surface in December and February to capture the first detailed images of Io’s northern latitudes.
It has been more than 20 years since a mission flew so closely by Io, and the spacecraft’s camera, called JunoCam, captured high-resolution images that showcased active volcanic plumes, mountain peaks, and a glass-smooth lake of cooling lava.
“Io is simply littered with volcanoes, and we caught a few of them in action,” said Scott Bolton, Juno’s principal investigator at the Southwest Research Institute, 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,” he added. “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.”
Bolton announced the findings on April 16 at the European Geophysical Union General Assembly in Vienna. The new data is painting a clearer portrait of Io, which has intrigued scientists for centuries.
“Other than the Earth, it’s the only place that we see active magma volcanoes going on in our solar system,” Bolton said.
The team also used the Atacama Large Millimeter/submillimeter Array of telescopes in Chile to observe gases in Io’s atmosphere. The researchers found evidence of an abundance of enriched sulfur and chlorine, which suggests that Io has likely been volcanically active and releasing the gases for most or all of its history over the past 4 billion years.
Io, first discovered by Galileo Galilei in 1610, is just slightly larger than our moon, but it’s unlike anywhere else in the solar system.
The rocky moon’s surface is covered with hundreds of volcanoes, drawing comparisons to the fictional volcanic planet Mustafar and its rivers of lava from the “Star Wars” films.
Scientists have observed Io’s powerful volcanoes spewing lava fountains that are dozens of miles high and can even be seen with large telescopes on Earth, according to NASA.
