From July 4th, NASA's Juno spacecraft is now in orbit around Jupiter. "NASA’s Juno spacecraft has successfully entered Jupiter’s orbit, bringing it closer to the planet than any probe has come so far. The vehicle reached the gas giant’s north pole this evening, and NASA received confirmation that the vehicle had turned on its main engine at 11:18PM ET. The engine burned for 35 minutes, helping to slow the spacecraft down enough so that it was captured by Jupiter’s gravitational pull. NASA confirmed that the burn was successful at around 11:53PM ET and that Juno was in its intended 53-day orbit."
But now, Juno is in a highly elliptical orbit around Jupiter that takes 53 days to complete. For most of that orbit, the spacecraft will be far out from Jupiter, avoiding its intense radiation belts and debris field. But at the end of the 53-day cycle, Juno will swing back close to the planet again. During this close pass, the vehicle will first fly over the north pole and then swoop in close over Jupiter's equator — squeezing in between the radiation belts and the planet's surface. Juno then swings back out into space over the planet's south pole.
This whole sequence of events, known as the Perijove pass, will take just a few hours to complete. But it's during this time that Juno will conduct the most science over Jupiter. The spacecraft's onboard instruments will be measuring the amount of water in Jupiter's atmosphere, as well as the planet's gravity and magnetic field. These measurements will help NASA figure out if Jupiter has a dense core underneath its surface. All of these details can be used to piece together exactly how and when Jupiter formed more than 4 billion years ago.
The two big close to Jupiter swings are scheduled for Aug 27th and Oct 19th.
In reality, NASA also now sentenced its $1.1 billion (~£850M) spacecraft to die. Mission managers hope to get 37 orbits out of Juno over the next 20 months before radiation slowly breaks down its electronics and propulsion system. Even though a 1cm-thick wall of titanium encases the spacecraft’s electronics to provide some protection, a few of its nine instruments may begin to fail in as few as eight or 10 orbits. Before the spacecraft fails entirely engineers will place Juno into a slowly degrading orbit that will eventually force it to plunge into the planet. This is so that none of its potentially life bearing moons, such as Europa, might be contaminated.
In other NASA news, The Verge reports Hubble is capturing stunning photos of Jupiter’s giant auroras