NASA's Juno Sees Changes at Masubi

The Stellar Reference Unit (SRU) on NASA's Juno spacecraft collected this visible wavelength image of Io's night side while the surface was illuminated by Jupiter-shine on April 4, 2024.

The image features the large compound flow field, Masubi, located on Io's southern hemisphere. Masubi was first observed by NASA's Voyager 1 in 1979 and has continued to expand ever since. A co-registered time sequence of Masubi observations covering 45 years is shown in the bottom panel. The location of the plume first observed by Galileo is circled in white in each image of the time sequence. The SRU observed even further expansion of pre-existing flows (white arrows) and two new flows with multiple lobes (yellow arrow).

As of April 4, 2024, Masubi's total compound flow length is about 994 miles (1,600 kilometers), making it the longest currently active lava flow in the solar system.

More information about Juno is at https://www.nasa.gov/juno and https://missionjuno.swri.edu.