The first spacecraft to probe deep underneath Jupiter's thick clouds is scheduled to arrive at the gas giant on July 4. Named Juno, the NASA orbiter will collect data that could elucidate the planet's origins and evolution, gather details about its long-lived storm (the Great Red Spot) and send back the highest-resolution color images of Jupiter to date.

Jupiter was apparently born from the leftover gas and dust of the primordial nebula that formed our sun, yet exactly how that birth occurred, or even whether the planet has a solid core, is unknown. “Learning about the formation of Jupiter enlightens us about the formation of all the planets and what went on in the early solar system,” says Scott Bolton, the project's principal investigator. With that objective in mind, the NASA team has programmed the sensor-laden Juno to measure the chemical composition of the planet's atmosphere and to map its gravitational and magnetic fields. The craft's microwave radiometer will also “see” about 550 kilometers below the clouds covering Jupiter's surface.

Juno is only the second space mission dedicated to the King of Planets, after the Galileo orbiter arrived in 1995 and spent eight years there. Juno's rendezvous will be much shorter: it will deorbit and burn up within Jupiter's atmosphere after about 20 months.

By the Numbers

2.8 Billion Kilometers

Total distance traveled

11 Solar Panels

Juno is the first solar-powered spacecraft to operate this far from the sun


Number of times Juno will orbit Jupiter’s poles

$1.1 Billion

Cost of mission to date