First science data from Juno shows Jupiter is a complex and chaotic planet

Jupiter has fascinated sky-gazers for millennia but it wasn’t until we sent probes to the planet that scientists began to unravel its deepest secrets. Now, new scientific data from Juno, the most recent spacecraft to rendezvous with the gas giant, shows that Jupiter has many more secrets still.

The recent results depict Jupiter as a highly complex and chaotic world, according to NASA, featuring cyclones the size of Earth and a surprisingly powerful magnetic field. The data was gathered during a few orbits around the planet, in which the probe came within just 2,600 miles of the top cloud layer, the closest any human-made hardware had ever passed. Two related papers have been published in the journal Science (here and here) and 44 have been published in Geophysical Research Letters.

“We knew, going in, that Jupiter would throw us some curves,” Scott Bolton, Juno principal investigator, said in a statement. “But now that we are here we are finding that Jupiter can throw the heat, as well as knuckleballs and sliders. There is so much going on here that we didn’t expect that we have had to take a step back and begin to rethink of this as a whole new Jupiter.”

One of the biggest surprises comes from data collected by the JunoCam, which revealed that Jupiter’s poles are surprisingly chaotic. Scientists expected to see something akin to the neat and orderly vortex found on Saturn. Instead, they’ve discovered densely packed and massive cyclones.

“We’re puzzled as to how they could be formed, how stable the configuration is, and why Jupiter’s north pole doesn’t look like the south pole,” Bolton said. “We’re questioning whether this is a dynamic system, and are we seeing just one stage, and over the next year, we’re going to watch it disappear, or is this a stable configuration and these storms are circulating around one another?”

A couple other surprises came from Jupiter’s gravitational and magnetic fields. Some of the data on the planet’s gravitational field defies computer models about the interior of the planet, reports Ars Technica, though more orbits will likely reveal to what extent the measurements are inconsistent.

Data about Jupiter’s magnetic field, on the other hand, conclusively shows that it’s about twice as strong as expected.

“Already we see that the magnetic field looks lumpy,” said Jack Connerney, Juno deputy principal investigator and lead for Juno’s magnetic field investigation, “it is stronger in some places and weaker in others. This uneven distribution suggests that the field might be generated by dynamo action closer to the surface, above the layer of metallic hydrogen. Every flyby we execute gets us closer to determining where and how Jupiter’s dynamo works.”

Juno is expected to orbit Jupiter for another two years before being retired, at which point it will dive into the planet’s atmosphere.