Four years ago, Juno discovered an octagon of eight cyclones at Jupiter’s northern pole and a similar five cyclone structure at its southern pole. Since then, both polygons have remained intact. What keeps the storm systems so stable is still an open question, but a recent observational study using Juno measurements found that an anticyclonic ring sits between the central and outer cyclones. In line with a previous theoretical study, this ring structure helps shield and stabilize the storm system.
The underlying convective mechanisms of the storm remain a mystery, though, as the current study is limited in resolution to a scale of about 200 kilometers. (Image credit: NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM; research credit: A. Ingersoll et al.; via Gizmodo)