Juno

Juno is a NASA mission that orbits Jupiter, the largest planet in the solar system, to study its interior, atmosphere and magnetic environment.^[1] It launched from Cape Canaveral, Florida, on 5 August 2011 and went into orbit around Jupiter nearly five years later, on 4 July 2016.^[1]

The mission

Juno first circled Jupiter in long orbits lasting 53 days, passing close over the cloud tops on each pass.^[1] The mission was first planned to explore Jupiter from 2016 to 2017.^[1] In 2021, NASA extended it with 42 additional orbits through September 2025.^[1] As an extended mission, Juno's changing orbit brought Jupiter's large moons within reach, and the spacecraft broadened its work to the whole Jovian system, including its rings and moons.^[1] Close passes of the volcanic moon Io in December 2023 and February 2024 shortened Juno's orbit to 33 days.^[1]

Among its findings are networks of vast storms around Jupiter's poles, active volcanoes and lava lakes on Io, and evidence that Jupiter's winds extend hundreds of miles into the planet.^[1]

Juno is also preparing the way for later visitors, including ESA's Juice mission, which launched in April 2023 and is scheduled to reach Jupiter in July 2031.^[1] When its work is done, Juno's orbit is to degrade and the spacecraft is to burn up in Jupiter's atmosphere.^[1]

Juno belongs to NASA's New Frontiers program of medium-sized missions, along with New Horizons and OSIRIS-REx.^[2] Jupiter's moon Europa is the target of Europa Clipper.