CAPE CANAVERAL, Fla. (AP) — Monstrous cyclones are churning over Jupiter's poles, until now a largely unexplored region.

NASA's Juno spacecraft spotted the chaotic weather once it began skimming Jupiter's cloud tops last year, surprising scientists who assumed the giant gas planet would be relatively boring and uniform down low.

"What we're finding is anything but that is the truth. It's very different, very complex," Southwest Research Institute's Scott Bolton, Juno's chief scientist, said Thursday.

With dozens of cyclones hundreds of miles across — alongside unidentifiable weather systems stretching thousands of miles — the poles look nothing like Jupiter's equatorial region, instantly recognizable by its stripes and Great Red Spot, a raging hurricane-like storm.

"That's the Jupiter we've all known and grown to love," Bolton told reporters. "And when you look from the pole, it looks totally different ... I don't think anybody would have guessed this is Jupiter."

He calls these first major findings — published Thursday — "Earth-shattering. Or should I say, Jupiter-shattering."

Turning counter-clockwise in the northern hemisphere just like on Earth, the cyclones are clearly clustered near the poles. The diameters of some of these cyclones stretch 870 miles (1,400 kilometers). Even bigger, though shapeless weather systems — spanning many thousands of miles — are present in both polar regions.

Launched in 2011 and orbiting Jupiter since last summer, Juno is providing the best close-up views ever of our solar system's largest planet. Besides polar cyclones, Juno has detected an overwhelming abundance of ammonia in Jupiter's deep atmosphere and a surprisingly strong magnetic field — roughly 10 times greater than Earth's.

"The results from Juno's initial close passes of Jupiter are changing our understanding of this gas giant," the researchers wrote in one of two articles that appeared in the journal Science.

Jupiter's poles appear dramatically different from neighboring Saturn's, according to the scientists, with nothing like the hexagon-shaped cloud system over Saturn's north pole.

Researchers hope to compare Juno's observations with those of NASA's Cassini spacecraft, in its final months orbiting Saturn.