Missions · Space Codex
Juno
Juno has orbited Jupiter since 2016, mapping its gravity, magnetic field and deep atmosphere, and flying close to Io, Europa and Ganymede.
NASA's Jupiter polar orbiter
At a glance
Key points
- In Jupiter orbit since July 2016
- Found a large, dilute core
- Close flybys of Io, Europa and Ganymede
A polar view
Juno's long elliptical orbits pass over the poles, revealing clusters of cyclones that Earth-based telescopes cannot see, and dip under the radiation belts at closest approach.
From planet mission to moon tour
The prime mission, a series of 53-day polar orbits, was due to finish in 2021. NASA then added 42 orbits and turned Juno into an explorer of the whole Jovian system. Each moon pass reshaped the orbit: Ganymede in June 2021, Europa in September 2022 at about 352 km, then two close Io passes in December 2023 and February 2024, the nearest any spacecraft had come to Io in two decades.
Solar power at five times Earth's distance
Unusually for an outer-planet probe, Juno runs on sunlight rather than a plutonium generator. Its three long solar wings must catch enough light at Jupiter, where the Sun is about 27 times dimmer than at Earth, so the arrays are far larger than a comparable spacecraft would need near home. Its electronics ride inside a shielded vault, because each close pass crosses the most intense radiation belts in the planetary system.
Status in 2026
NASA's last published extension ran to September 2025 or the end of the spacecraft's life, and the agency has not issued a clear statement since. A 2026 conference abstract by members of the science team lists planned perijoves every 33 days or so, from PJ87 in September 2026 to PJ98 in September 2027, which implies the spacecraft is still operating. Treat that as likely but not officially confirmed.
What we still don't know
How long the spacecraft will keep operating, and how Jupiter's dilute core formed.
Missions
- 2011–
Juno
NASAActiveIn Jupiter orbit since Jul 2016 on an extended mission. NASA's status page is inconsistent; perijoves are planned into 2027.
Related entries
Sources
- NASA Science: Juno (opens in a new tab)
- Orton, Bolton et al., EPSC 2026 abstract (opens in a new tab)
- NASA Science: Io (opens in a new tab)
- NASA Science: Jupiter facts (opens in a new tab)
- NASA: Juno exploring Jovian moons during extended mission (opens in a new tab)
- NASA JPL: Juno shares first image from Europa flyby (opens in a new tab)
- NASA JPL: Juno mission overview (opens in a new tab)
- NASA Science: Juno's mission goes on (2021) (opens in a new tab)
Last reviewed against these sources. Built from public NASA, ESA and JPL data; not affiliated with or endorsed by any agency.