Juno will be the first long-term mission in Jupiter's system since the Galileo mission, which ran in the 1990s and 2000s. Juno will arrive on July 4 and make an incredible, 106-day orbit before settling into a mapping orbit that will bring it roughly 3,000 miles above Jupiter at its closest. The spacecraft will regularly whizz out closer towards Jupiter's moons to avoid radiation from the giant planet, then pull back in to do more mapping. Its nominal mission ends in 2017, but could be extended if the spacecraft is healthy and funds permit.
Juno will probe the origins of Jupiter, such as how the planet was formed, whether it has a core, and how its magnetic field behaves. The answers are supposed to yield some clues about how the solar system came to be. Also, when we learn about Jupiter we may be able to extrapolate some of the findings to Jupiter-sized exoplanets, giving us thoughts about solar system creation more generally in the universe.
Image: Artist's impression of the Juno mission at Jupiter. Credit: NASA