NASA's Juno shows 127-mile-long lava lake on Jupiter's moon

NASA’s Juno shows 127-mile-long lava lake on Jupiter’s volcanic moon

Juno made extremely close flybys of Io, Jupiter’s moon, in December 2023 and February 2024, obtaining the first close-up images of the moon’s northern latitudes.

NASA’s Juno shows 127-mile-long lava lake on Jupiter’s volcanic moon

The Juno spacecraft


NASA launched Juno, the solar-powered spacecraft back in 2011. It took about six years for Juno to cruise over to Jupiter. Juno looks like a propeller that’s been orbiting around our solar system’s biggest planet for about eight years now. It has captured some stunning images and collected groundbreaking data.

Now, Juno has cruised over to Io, NASA reports, the world’s most volcanically active spot in the solar system. That’s what scientists are actually studying. After all, Juno cost like a billion dollars to build.

Science wants the 411 on the water situation on Jupiter. It could provide clues as to how our solar system formed as Jupiter is not only the largest but the first planetary body, most likely.

Juno is studying the water situation on Jupiter

Until Juno, scientists didn’t know how much water there was on Jupiter. Scott Bolton, principal investigator, stated previously that “no one would have guessed that water might be so variable across the planet.”

“Now, with recent results made with MWR data,” he confirmed, “we have nailed down that the water abundance near Jupiter’s equator is roughly three to four times the solar abundance when compared to hydrogen.

NASA isn’t looking for liquid water. They want to know how much oxygen and hydrogen molecules are in Jupiter’s atmosphere. This is critical piece in the puzzle of how this solar system came into being.  

After zooming in on the equator, “this definitively demonstrates that the Galileo probe’s entry site was an anomalously dry, desert-like region.”

Galileo was the last spacecraft that cruised around Jupiter back in 1995. That mission changed our understanding of the solar system but left NASA with more questions than answers. That’s why they sent Juno.

“The probe did amazing science, but its data was so far afield from our models of Jupiter’s water abundance that we considered whether the location it sampled could be an outlier. But before Juno, we couldn’t confirm,” said Bolton. 

This animation is an artist’s concept of Loki Patera, a lava lake on Jupiter’s moon Io/NASA/JPL-Caltech/SwRI/MSSS

NASA is getting closer to understanding how our solar system formed

The data now supports the theories that “during the formation of our solar system, water-ice material may have been the source of the heavy element enrichment (chemical elements heavier than hydrogen and helium that were accreted by Jupiter) during the gas giant’s formation and/or evolution.”

So how did Jupiter form? NASA doesn’t know. Juno is showing them that “the core of the gas giant suggests a very low water abundance.”

This doesn’t make sense to NASA.

Juno thus extended its mission to study the situation more in-depth. It cruised on over to Io to a remarkable closeness: 10,250 miles (16,500 kilometers) of the moon’s surface. It captured some close-ups of the most volatile body in our solar system.

NASA just transformed the data Juno sent over into animations to help us lay folks admire a dramatic mountain and a lake of cooling lava as smooth as glass. Scientists have never gotten this close before.

“Io is simply littered with volcanoes, and we caught a few of them in action,” said Bolton. “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.”


The study of Jupiter’s polar cyclones and water abundance continues as NASA solves the puzzle of how our solar system formed.

Juno’s mission is set to continue until September 2025 or when its life comes to an end. Thanks to her brief but important life, we might find out how our solar system formed (once NASA makes sense of Jupiter’s water situation).

An artist’s concept of a feature on the Jovian moon Io nicknamed “Steeple Mountain.” NASA/JPL-Caltech/SwRI/MSSS
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Maria Mocerino Originally from LA, Maria Mocerino has been published in Business Insider, The Irish Examiner, The Rogue Mag, Chacruna Institute for Psychedelic Plant Medicines, and now Interesting Engineering.