NASA’s Juno spacecraft on Dec. 30, 2023 made the closest flyby of Jupiter’s moon Io that any spacecraft has made in more than 20 years. Coming within roughly 930 miles (1,500 kilometers) from the surface of the most volcanic world in our Solar System, the pass is expected to allow Juno instruments to generate a firehose of data.
During the flyby the spacecraft’s JunoCam captured its highest resolution image of Io. Planetary Science Institute Senior Scientist Candy Hansen is a Juno co-investigator who leads planning for the JunoCam public-engagement camera.
A second ultra-close flyby of Io is scheduled for Feb. 3, 2024, in which Juno will again come within about 930 miles (1,500 kilometers) of the surface.
The closest flyby of Io was when NASA’s Galileo spacecraft passed within about 181 kilometers (112 miles) of ground level near Io’s south pole on Oct. 15, 2001 during the spacecraft’s 32nd orbit around Jupiter.
The spacecraft has been monitoring Io’s volcanic activity from distances ranging from about 6,830 miles (11,000 kilometers) to more than 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.