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First results from Juno mission show surprisingly strong magnetic field and huge polar cyclones

  • Juno mission data is causing scientists to rethink understanding of Jupiter.
  • Jupiter has massive polar cyclones and a bigger magnetic field than expected.
  • 46 total papers published this week in two different journals.
This image shows Jupiter’s south pole, as seen by NASA’s Juno spacecraft from an altitude of 32,000 miles (52,000 kilometers). The oval features are cyclones, up to 600 miles (1,000 kilometers) in diameter. Multiple images taken with the JunoCam instrument on three separate orbits were combined to show all areas in daylight, enhanced color, and stereographic projection.
Betsy Asher Hall / Gervasio Robles | JPL-Caltech | SwRI/MSSS | NASA
This image shows Jupiter’s south pole, as seen by NASA’s Juno spacecraft from an altitude of 32,000 miles (52,000 kilometers). The oval features are cyclones, up to 600 miles (1,000 kilometers) in diameter. Multiple images taken with the JunoCam instrument on three separate orbits were combined to show all areas in daylight, enhanced color, and stereographic projection.

Scientists just released a pile of more than 40 scientific papers discussing some stunning data from NASA's mission to Jupiter.

The Juno mission has observed huge cyclones at Jupiter's poles, and a magnetic field around the planet that is both larger than scientists expected, and surprisingly irregular in shape. The findings are the first of likely several papers revealing an unprecedented amount of information about the largest planet in the solar system.

The researchers published two papers Thursday in the journal Science, and 44 papers in the journal of Geophysical Research Letters.

"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," said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio, in a news release.

In one paper published in Science, researchers said the spacecraft's JunoCam caught images of massive storms, one of which was 800 miles in diameter, at Jupiter's poles. The researchers said they are not sure as to how the cyclones are formed, how stable the configuration is, and why the north pole of the planet looks different than the south pole.

"We're questioning whether this is a dynamic system," said Bolton, who was lead author of the paper, "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?"

Measurements of the thermal structure of Jupiter's atmosphere also revealed some unexpected structures beneath its cloud tops, which the researchers think is ammonia welling up from the deepest portions of the atmosphere and creating storms.

Scientists already knew Jupiter had a strong magnetic field, but new data discussed in the second Science paper say it is much larger than they had thought, and appeared to be irregularly shaped.

"Already we see that the magnetic field looks lumpy: it is stronger in some places and weaker in others," said that paper's lead author Jack Connerney, who is Juno deputy principal investigator and the lead for the mission's magnetic field investigation at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "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."

Data also seems to suggest Jupiter's auroras — sometimes compared to the northern and southern lights on Earth — are caused by an entirely different process. On Jupiter, the auroras are formed by particles that accrue energy and smash into molecules in the atmosphere.

The Juno mission launched in 2011 and reached Jupiter in 2016. Its primary goal is to understand how Jupiter formed and changed over time. The craft will orbit Jupiter 37 times, before descending into Jupiter's atmosphere in February 2018.