Some odd storms on Jupiter discovered back in 2017 by a NASA spacecraft are particularly intriguing to scientists. New research attempted to figure out how the nine cyclones spinning at Jupiter’s north pole remain so organised.
Jupiter’s iconic Great Red Spot is actually a mass of swirling storm clouds called an anticyclone, and it’s only one of many storms on the gas giant. At Jupiter’s north pole, there is a family of nine cyclones — one large storm surrounded by eight smaller ones — that was first noticed in 2017 by NASA’s Juno spacecraft, which orbits the planet. A study published in Nature Astronomy examined why this configuration has stayed stable for the last few years, if not long before its discovery.
“Since 2017 the Juno spacecraft has observed a cyclone at the north pole of Jupiter surrounded by eight smaller cyclones arranged in a polygonal pattern,” the study authors write. “It is not clear why this configuration is so stable or how it is maintained.”
Jupiter’s south pole features a similar configuration, except with five storms forming a pentagon, as opposed to the eight at the north pole that form an octagon. The researchers refer to the geometric north and south pole storm systems as “polygons” and write: “The polygons and the individual vortices that comprise them have been stable for the 4 years since Juno discovered them. The polygonal patterns rotate slowly, or not at all.”
The researchers used a series of images from Juno’s Jovian Infrared Auroral Mapper, or JIRAM, to study the behaviour of these storms. They found that an “anticyclonic ring” surrounds the central storm, spinning in the opposite direction as the main cyclone. This ring, the researchers argue, could serve to stabilise the system.
The storms on Jupiter are a striking example of the intense meteorology that can occur on other planets. On Saturn, another gas giant planet, a massive hexagonal jet stream covers the north pole. It’s even been known to change colour.