Artist's impression of Juno & Jupiter
Credit: NASA/Juno

Juno is a NASA spacecraft orbiting the planet Jupiter. It was launched in August 2011 as part of NASA's New Frontiers program, and entered orbit around Jupiter in July 2016. Juno is the second mission to orbit Jupiter; the Galileo spacecraft orbited the planet from 1995 to 2003.

Juno's scientific goals are to study Jupiter's composition, gravity field, and magnetic field. It will investigate how the planet formed, whether it has a rocky core, how much water it contains, and why it has such strong winds.

Juno is the only spacecraft which orbits an outer planet to rely on solar power. Many satellites which orbit the Earth and the inner planets use solar power, whereas more distant spacecraft usually generate power using radioactive materials. The Juno spacecraft has the three largest solar panels ever built on a planetary spacecraft, which generate enough electricity to power Juno.

Photographs of Jupiter's Great Red Spot have been taken by Juno (pictured below). Scientists are able to study in detail the complex storm systems of Jupiter, to understand more about Jupiter's atmosphere: its pressure, temperature, structure, and composition.

Juno photograph of the Great Red Spot
Enhanced colour image of Jupiter's Great Red Spot, taken by Juno
Credit: NASA/K Gill