Jupiter’s massive polar cyclones
NASA’s Juno spacecraft has revealed Jupiter to be a far more turbulent and varied world than expected, reports ScienceNews.org. Images and other data the probe has been streaming back as it orbits the gas giant have revealed many surprises: polar cyclones nearly 900 miles wide, a powerful and irregular magnetic field about 10 times stronger than the strongest part of Earth’s magnetic field, and a concentrated band of ammonia near the planet’s equator. Juno has made five highly elliptical orbits since last July. Each one has brought the $1.1 billion probe as close as 2,100 miles to Jupiter’s atmosphere, enabling its cloud-piercing instruments to collect detailed data and take close-up photographs. The cyclones make the planet’s poles look completely different from its equatorial regions, where various gases create Jupiter’s distinctive striped look. The magnetic field is twice as strong as anticipated, and the powerful polar auroras work differently from how they do on Earth. And the band of ammonia is much more geographically concentrated than scientists expected. “We went in with a preconceived notion of how Jupiter worked,” says mission leader Scott Bolton, “and I would say we have to eat some humble pie.” One mystery Juno hasn’t yet solved is whether the planet’s core is solid or gaseous. So far the data suggest it is in fact “fuzzy,” because it is partially dissolved.