Will Juice fly past Kallichore?

The 2031 opportunity, and why the moon’s position must be pinned down first.

Published 2026-10-23

Juice could become the first spacecraft to study one of Jupiter’s small outer moons up close.^[1]

The mission

Juice launched from French Guiana on 14 April 2023 and is expected to reach Jupiter in July 2031 after four gravity assists.^[3]

The baseline pass

Juice is predicted to pass within 1 million km of Kallichore on 7 October 2031, during its first orbit of Jupiter.^[1]

Getting closer

A 2026 study by Arnaud Boutonnet and Amedeo Rocchi found Juice could come much closer by spending at least 23 m/s of delta-v. To resolve Kallichore beyond one pixel with its JANUS camera, Juice must come within 100,000 km. One trajectory could pass as close as 700 km on 5 October 2031.^[1]

The catch

As of March 2026, Kallichore’s predicted position on the flyby date is uncertain by ±272 km. That must be cut below ±30 km by 2028 before a decision can be made.^[1]

Numbered citations link to the sources list on the Kallichore overview page.