Surprise! Jupiter’s Poles are Literally Encircled by Cyclones
If you think that Saturn’s polar storm systems are amazing then you’re gonna love this: Jupiter has them too, and not just a single central storm over each of its poles either. NASA’s Juno mission has revealed that Jupiter has not only polar vortices but also a ring of enormous cyclones spinning in formation around both of its poles—five around its south pole and a whopping eight around its northern one! Each of these cyclones is gargantuan in its own right, easily big enough to span the Atlantic Ocean, and somehow they all manage to avoid merging with their respective neighbors via some as-yet unknown process. It’s literally like nothing found anywhere else in the Solar System!
The image above was is made of data acquired by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA’s Juno spacecraft, now over a year and a half into its mission in orbit around Jupiter. It shows Jupiter’s north pole in infrared light, over which a single cyclonic storm rotates with eight distinct cyclones surrounding it.
At Jupiter’s south pole a similar central cyclone was observed with five separate storms around it.
With JIRAM aboard Juno, scientists are able to measure the temperatures of Jupiter’s atmosphere 30 to 45 miles (50 to 70 km) down into Jupiter’s clouds. The colors in the images represent radiant heat; the yellow clouds are about 9 degrees Fahrenheit (-13°C) in temperature and the dark red are around 181 degrees Fahrenheit (83°C).
(Remember too that the images above were made from infrared observations; in visible light Jupiter’s poles don’t look nearly as infernal!)
Unlike Earth, Jupiter’s axial tilt is quite subtle—only about 3º (compared to Earth’s 23.4º). This means that Jupiter’s polar regions cannot be well observed from here…it took putting a spacecraft into a highly-inclined orbit (like Juno) to get good views of the giant planet’s poles.
“Prior to Juno we did not know what the weather was like near Jupiter’s poles. Now, we have been able to observe the polar weather up-close every two months,” said Alberto Adriani, Juno co-investigator from the Institute for Space Astrophysics and Planetology in Rome and lead author of the paper published in Nature. “Each one of the northern cyclones is almost as wide as the distance between Naples, Italy and New York City—and the southern ones are even larger than that. 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.”
These images were actually first revealed during the 231st AAS meeting in Washington, DC in January 2018 by Juno principal investigator Scott Bolton. Just for fun I had taken the map-projected images shared on Twitter and made an animation of them as if you were watching them rotate….check it out. Wheeeeee! 🙂
The solar-powered Juno spacecraft launched aboard a ULA Atlas V 551 rocket from Cape Canaveral on Aug. 5, 2011. After nearly five years and 1.7 billion miles of travel Juno arrived in orbit at Jupiter on July 4, 2016.