Frontiers Physics World  May 2018

Persistent storms

(NASA / JPL-Caltech / SwRI / ASI / INAF / JIRAM)

Rather than a representation of an organized fiery hell, this is an image of Jupiter’s north pole. Based on infrared data collected by Juno’s Jovian Infrared Auroral Mapper (JIRAM), it shows the pole’s odd arrangement of cyclones, which scientists have now discovered are remarkably persistent. The north pole has nine storms – with eight circling one that sits at the pole and each one being around 4000–4600 km in diameter. Meanwhile, the south pole is home to five cyclones circling a sixth, each around 5600–7000 km across. In both cases, the position and shapes of the cyclones remained more or less the same over hundreds of days of observation. The finding has the team baffled, as fluid dynamics cannot explain how the cyclones and patterns do not appreciably change over time, or why the storms do not interact with each other (Nature 555 216).

Hamish Johnston