NASA’s Juno spacecraft has been orbiting Jupiter for nearly a year now — and the space probe is revealing the gas giant to be more complex and surprising than we ever thought.
Juno’s instruments show that massive cyclones dominate the planet’s poles, while a deep tropical band of ammonia circles its equator. Meanwhile, the planet’s magnetic field is turning out to be much stronger than expected and the gravity field is indicating that Jupiter’s interior core may not be super dense. All these findings, published in two new studies today in Science, as well as 44 in the journal Geophysical Research Letters, will eventually help planetary scientists piece together the structure of Jupiter. And that could tell us a lot about how the planet formed billions of years ago.
These new tantalizing clues about Jupiter were gathered by Juno during the its first couple of passes by the planet. Right now, Juno is in an extremely elliptical orbit, which brings the probe screeching by Jupiter’s surface for a few hours at a time during each trip around the planet. These passes, known as Perijove passes, bring Juno over the planet’s poles — closer than any previous vehicle has gone before. And it’s during these swings by Jupiter that Juno gathers the bulk of its data.
“Juno is the right tool to sort this out.”
Currently Juno does one Perijove pass every 53 days, though the original plan was one pass every 14 days. (Engine problems messed up the plan, so Juno is going to remain in its much longer orbit for the rest of its lifetime.) That just means it’s going to take longer to get answers about Jupiter than the mission team wanted. And the researchers are hesitant to make conclusions about Jupiter’s origins until the probe has passed by the planet a few more times.