JunoCam Spots New Active Volcano on Io Island

A new volcano has been spotted on Jupiter’s moon Io, the most geologically active place in the solar system. Analysis of the first close-up images of Io in more than 25 years, taken by the JunoCam instrument on NASA’s Juno mission, reveals the emergence of a new volcano with multiple lava flows and volcanic deposits covering an area about 180 kilometers by 180 kilometers. The results were presented at the Europlanet scientific conference (EPSC 2024) in Berlin this week.

The new volcano is located just south of Io’s equator. Although Io is covered in active volcanoes, images taken by NASA’s Galileo mission in 1997 failed to show any volcanoes in this particular region, just a featureless surface.

“Our recent JunoCam images show many changes on Io, including this large, complex volcanic structure that appears to have formed out of nothing since 1997,” said Michael Ravine, advanced projects manager at Malin Space Science Systems, Inc., which designed, developed and operates JunoCam for NASA’s Juno project.

The eastern side of the volcano is tinged with a diffuse red due to sulfur that was released from the volcano into space and fell back onto Io’s surface. On the western side, two dark lava flows have erupted, each extending for about a hundred kilometers.

At the furthest point of the flows, where the lava accumulated, the heat caused the frozen material on the surface to vaporize, generating two superimposed gray circular deposits.

The best JunoCam image of this formation, east of an existing volcano called Kanehekili, was taken on February 3, 2024, from a distance of 2,530 kilometers and at a scale of 1.7 kilometers per pixel. The images were captured on the far side of Io with illumination coming only from Jupiter.

This encounter was one of three recent flybys of Io in 2023 and 2024, during which JunoCam acquired about 20 close-up color images. JunoCam observed a total of nine plumes associated with active volcanic features on the moon, as well as other changes, such as new lava flows and other surface deposits.

JunoCam data is published on the mission’s website shortly after it is received on Earth to allow the public to create images of Jupiter and its moons.

“JunoCam images are created by people from all walks of life, providing a way for everyone to join our science team and share in the excitement of space exploration,” said Scott Bolton, NASA’s Juno mission principal investigator at Southwest Research Institute.