Five Images of Io from Juno Perijove 49

2023-03-04 05:58 UT
Credit : NASA / SwRI / MSSS / Jason Perry © cc by
Submitted By : JasonPerry
Mission Phase : PERIJOVE 49

On March 1, 2023, the Juno spacecraft flew by Io at an altitude of 51,570 kilometers (32,044 miles), providing JunoCAM with an opportunity to acquire these five images of Io. These provide JunoCAM's best images so far of Io's colorful surface.

Most of the dark spots seen across Io's surface are the result of volcanic eruptions. These include East Girru, a dark spot that was not seen the last time Io was seen at this resolution during the New Horizons encounter with Jupiter in February 2007. East Girru was undergoing a major eruption at the time but hadn't had time to produce a new lava flow before the end of the week-long encounter. This small flow field, measuring 3,200 square kilometers (1,390 square miles) in size, may have also been reactivated during an eruption in October 2021, as seen by Juno JIRAM. Another apparent surface change is at Chors Patera, which has undergone a significant reddening since Galileo last observed it in October 2001. Reddish materials on Io are indicative of the presense of short-chain sulfur and are often associated with high-temperature, silicate volcanism. Additional dark spots near the terminator, the boundary between Io's day and night sides, are the shadows of tall mountains. The dark spot at middle right in the upper right image may be due a mountain 5500 meters (18,000 feet) tall.

The original JunoCAM observations were reprojected to point perspective map projection and enlarged by 10x to improve the visibility of surface features. The original resolution of these images varied from 43 kilometers (26 miles) to 34 kilometers (21 miles) per pixel.