NASA’s Juno Spacecraft to Perform Closest Flyby of Jupiter’s Moon Io in Over 20 Years
The Juno spacecraft, a part of NASA’s New Frontiers Program, has made a total of 56 flybys of Jupiter and documented close encounters with three of the gas giant’s four largest moons. It is now set to make history by performing the closest flyby of Jupiter’s moon Io that any spacecraft has made in over 20 years.
Scheduled for Tuesday, December 30, the flyby is expected to bring Juno within roughly 930 miles (1,500 kilometers) from the surface of Io, known as the most volcanic world in our solar system. The close pass is anticipated to allow Juno’s instruments to generate a plethora of data that will help the Juno science team study how Io’s volcanoes vary.
Juno has been monitoring Io’s volcanic activity from varying distances, ranging from about 6,830 miles (11,000 kilometers) to over 62,100 miles (100,000 kilometers), and has provided the first views of the moon’s north and south poles. The spacecraft has also performed close flybys of Jupiter’s icy moons Ganymede and Europa.
In addition to the upcoming ultra-close flyby of Io on February 3, 2024, Juno will investigate the source of Io’s massive volcanic activity, whether a magma ocean exists underneath its crust, and the importance of tidal forces from Jupiter, which are relentlessly squeezing this tortured moon.
All three cameras aboard Juno will be active during the upcoming Io flyby, capturing infrared images of the heat signatures emitted by volcanoes and calderas covering the moon’s surface. The Stellar Reference Unit will obtain the highest-resolution image of the surface to date, while the JunoCam imager will take visible-light color images. In addition, Juno’s Gravity Science experiment will be used to probe Jupiter’s upper atmospheric makeup, providing key information on the planet’s shape and interior structure.
Juno’s orbit around Jupiter will be reduced from 38 days to 35 days after the flyby on December 30, and then to 33 days after the flyby on February 3. The spacecraft will encounter solar eclipses during every close flyby of Jupiter from now on, with the exception of the February 3 perijove, but the duration will be too short to affect its overall operation.
The Juno spacecraft is part of NASA’s New Frontiers Program and is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington. More information about Juno is available at the official NASA website.