The Juno probe is due to reach the gas giant on July 4 after a five-year, 1.4 billion-mile journey from Earth. It will enter a long polar orbit flying to within 2,900 miles (4,667 km) of the planet's swirling cloud tops. Once in orbit around Jupiter, Juno will skim just 5000 km above Jupiter's clouds once a fortnight - too close to provide global coverage in a single image. The Earth-based observations supplement the suite of advanced instrumentation on the Juno spacecraft, filling in the gaps in Juno's spectral coverage and providing the wider global and temporal context to Juno's close-in observations. It will enter a long polar orbit flying to within 2,900 miles (4,667 km) of the planet's swirling cloud tops. No previous spacecraft has orbited so close to Jupiter, although two others have been sent plunging to their destruction through its atmosphere. To complete its risky mission Juno will have to survive a circuit-frying radiation storm generated by Jupiter's powerful magnetic field. The maelstrom of high energy particles travelling at nearly the speed of light is the harshest radiation environment in the Solar System. To cope with the conditions, Juno is protected with special radiation-hardened wiring and sensor shielding. Its all-important 'brain' - the spacecraft's flight computer - is housed in an armoured vault made of titanium and weighing almost 400 pounds (172kg). Juno was launched on Aug. 5, 2011. The spacecraft will orbit the Jovian world 33 times, skimming to within 3,100 miles (5,000 kilometers) above the planet's cloud tops every 14 days. During the flybys, Juno will probe beneath the obscuring cloud cover of Jupiter and study its aurorae to learn more about the planet's origins, structure, atmosphere and magnetosphere. Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife - the goddess Juno - was able to peer through the clouds and reveal Jupiter's true nature.