JUICE

At a glance

Key points

• First planned orbit of a moon other than Earth's
• Jupiter arrival July 2031
• Earth flyby completed 28 Sep 2026

A tour that ends in orbit

After years of Jupiter orbits with flybys of Europa, Callisto and Ganymede, JUICE will brake into orbit around Ganymede, the only moon with its own magnetic field.

Detours on the way

The cruise uses four gravity assists. Along the way JUICE also observed the interstellar comet 3I/ATLAS in 2025–26.

The September 2026 Earth flyby

At 11:45 UTC on 28 September 2026 JUICE passed 8,640 km above the Indian Ocean. Earth's gravity bent its path by about 20° and added 3.5 km/s. Flight controllers needed only one of six planned trajectory corrections, which leaves more propellant for the Jupiter tour. The pass doubled as the third in-flight test of all ten instruments: cameras photographed Madagascar and the Moon, and the fields and particle sensors spent several days inside Earth's magnetic tail.

Why the solar wings are so large

At Jupiter's distance a solar panel receives only about one twenty-seventh of the sunlight it would near Earth. To run ten instruments that far out, JUICE carries 85 m² of solar wings. Earlier outer-planet explorers such as Voyager, Galileo and Cassini used plutonium generators instead; JUICE follows NASA's Juno in showing that sunlight alone can power a Jupiter orbiter if the arrays are big enough.

Settling around Ganymede

In December 2034 JUICE is planned to brake into an elongated orbit around Ganymede, then lower it to a circular orbit about 5,000 km up and later to about 500 km. From there it will map the surface, sound the ice and watch how Ganymede's own magnetic bubble sits inside Jupiter's much larger one. The orbit slowly decays, and the mission is planned to end with an impact on Ganymede in 2035.

What we still don't know

How deep Ganymede's ocean sits under its ice, and how the moon's magnetic field interacts with Jupiter's.

Missions

1. 2023–

   JUICE

   ESAEn route

   Earth flyby Sep 2026, another in Jan 2029; Jupiter arrival Jul 2031, then orbit Ganymede.

   Mission page (opens in a new tab)

Related entries

• GanymedeThe largest moon in the Solar System
• EuropaAn ocean world under ice
• CallistoThe most heavily cratered object known
• Europa ClipperNASA's ocean-world explorer

Sources

1. ESA: Juice (opens in a new tab)
2. ESA: Successful Earth flyby improves Juice's course (opens in a new tab)
3. ESA Cosmos: Juice overview (opens in a new tab)

Last reviewed 10 Oct 2026 against these sources. Built from public NASA, ESA and JPL data; not affiliated with or endorsed by any agency.