These insane new images of Jupiter’s poles were captured by the Juno spacecraft’s Jovian Infrared Auroral Mapper or JIRAM. JIRAM examines the planet in infrared light, so it can see deep into Jupiter’s atmosphere day or night, as far down as 30 to 45 miles (50 to 70 km). The camera is something like the thermal cameras firefighters use to locate people trapped in a house fire.
Because Juno’s orbit takes it over the planet’s poles every couple months, we’re getting our first clear views of the planet’s polar weather. From Earth, it’s impossible to view the polar regions in much detail because Jupiter’s axis is tilted only 3°. We can’t look over the top or under the bottom the way Juno can.
“Each one of the northern cyclones is almost as wide as the distance between Naples, Italy and New York City (~4,400 miles) — and the southern ones are even larger than that,” said Alberto Adriani, Juno co-investigator. “They have very violent winds, reaching, in some cases, speeds as great as 220 mph (350 kph). Finally, and perhaps most remarkably, they are very close together and enduring. There is nothing else like it that we know of in the solar system.”
I’ll say. Jupiter’s polar whirlpools stand in stark contrast to the more familiar red-brown belts and white zones that stripe the planet at lower latitudes. In infrared, the north pole is dominated by a huge central cyclone surrounded by eight circumpolar cyclones with diameters ranging from 2,500 to 2,900 miles (4,000 to 4,600 km) across. Jupiter’s south pole also contains a central cyclone surrounded by five cyclones with diameters ranging from 3,500 to 4,300 miles (5,600 to 7,000 km) in diameter.
Despite rubbing elbows, each cyclone has remained distinct and separate over seven months of observations detailed in a series of papers published March 8 in the journal Nature. Why don’t they merge? At Saturn, each pole has only a single vortex.
Juno data also revealed that Jupiter’s atmospheric winds run deep and last longer than similar winds found on Earth. Astronomers have long been mystified as to how deep the planet’s belts and zones go. Gravity measurements collected by Juno during its close flybys of the planet have now provided an answer. The deeper the jets, the more mass they contain and the stronger the signal they show in the planet’s gravity field.
“Galileo viewed the stripes on Jupiter more than 400 years ago,” said Yohai Kaspi, another Juno co-investigator. “Now, following the Juno gravity measurements, we know how deep the jets extend and what their structure is beneath the visible clouds. It’s like going from a 2-D picture to a 3-D version in high definition.”
The result was a big surprise. The Jovian weather layer reaches from the cloud tops 1,900 miles (3,000 km) down or nearly the diameter of the moon. Given that Jupiter’s 86,880 miles (139,820 km) across, that’s a massive amount of clouds, storms and jet streams to move it all along. You gotta love all that weather.
Juno reveals the depth of Jupiter’s cloud belts
Another Juno result released today suggests that beneath the weather layer, the planet rotates nearly as a rigid body. Like a slow-spinning bowling ball wrapped in a whirl of weather. Scientists hope that future measurements from Juno will help us understand the divide.