NASA spacecraft and mission to Jupiter. The probe launched in 2011 and has been in orbit around the gas giant since July 2016. Juno’s main goal is to improve our understanding of the Solar System’s beginnings by revealing the origin and evolution of Jupiter. Specifically, the probe is equipped with diverse instruments to conduct four primary missions: (1) to determine the amount of water in Jupiter’s atmosphere; (2) to measure composition, temperature, cloud motions, and other properties of Jupiter’s deep atmosphere; (3) to map Jupiter's magnetic and gravity fields; and (4) to explore and study Jupiter's aurorae. The Juno mission is the second spacecraft designed under NASA’s New Frontiers Program and the second long-term mission at Jupiter after the Galileo spacecraft. Juno has made several important discoveries, including that there are giant cyclones at the planet’s poles, that high-altitude clouds snow material onto Jupiter’s cloud tops, that Jupiter’s bands extend deeper into the planet’s atmosphere, that its core is larger and more diffuse than previously thought, and that the planet’s aurorae are different from those on Earth.

NASA ’s Juno spacecraft in orbit above Jupiter’s Great Red Spot.

Credit: NASA