Peering beneath Jupiter's clouds
Juno
Juno has orbited Jupiter since July 2016, swinging over the planet's poles on long, elliptical loops to probe what lies beneath the cloud tops. It is the first solar-powered spacecraft to operate so far from the Sun.
Its extended mission added close flybys of the Galilean moons Ganymede, Europa and Io.
Key facts
- Agency
- NASA / JPL
- Launched
- 2011-08-05
- Launch vehicle
- Atlas V 551
- Power
- Solar arrays
- Mission type
- Orbiter
- Arrival at Jupiter
- July 2016
- Status
- In orbit around Jupiter (extended mission approved through September 2025; check NASA for current status)
Where it is now
Loading live position from NASA/JPL Horizons…
Jupiter orbit.
Mission objectives
Juno was built to answer how Jupiter formed and evolved: how much water it contains, whether it has a solid core, how its deep atmosphere moves and how its powerful magnetic field and aurorae are generated.
The spacecraft
Three large solar arrays give Juno a span of about 20 m. Its most sensitive electronics sit inside a titanium vault that shields them from Jupiter's intense radiation belts.
Instruments
Juno carries a microwave radiometer that sees deep into the atmosphere, a magnetometer, gravity science radio equipment, infrared and ultraviolet spectrometers, particle detectors and JunoCam, a camera whose images are processed by members of the public.
Discoveries and highlights
Juno found that Jupiter's core is large and 'fuzzy' rather than compact, imaged clusters of cyclones arranged in geometric patterns around both poles, and showed that the planet's belts and zones extend thousands of kilometres deep. Its close flyby of Io revealed new details of the moon's volcanic surface.
Route and timeline
- 2011-08-05Launch, Cape Canaveral
- 2013-10-09Earth gravity assist
- 2016-07-05Entered orbit around Jupiter
- 2021-06-07Ganymede flyby
- 2022-09-29Europa flyby
- 2023-12-30Close Io flyby
Surprising facts about Juno
- Juno carries three small Lego figures: Galileo, and the Roman deities Jupiter and Juno.
- It flies over Jupiter's poles, which earlier missions never saw clearly.
- Its solar arrays receive about 25 times less sunlight than they would at Earth.