A zoom of a Dec. 30, 2023, image from the Stellar Reference Unit (SRU) aboard NASA's Juno spacecraft shows Io's night side while illuminated by Jupiter-shine. A strong stretch has been applied to highlight features observed by the SRU in the Zal Montes-Patera region, including a new 25-mile-long (41-kilometer-long) branch of fresh lava flow (indicated by the orange arrow) located to the west of Zal Patera's prior western boundary.

A new bright ring segment (indicated by the yellow arrow) is seen to the south of the new flow and may be associated with its formation. A possible low-angle jet of vaporized sulfur dioxide frost (circled in white) is observed at one of the lobed fronts of the new flow and is the first observation of a "Promethean-type jet" on Io since the original discovery at Prometheus by NASA's Galileo mission in 1999-2000.

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