207 — Clusters of cyclones encircling Jupiter’s poles

The recent images returned from the Juno probe’s perijove orbits are honestly some of the most incredible photographs I’ve ever seen — and this is coming from the guy who teared up during an IMAX movie about Hubble.

Because Jupiter’s equator almost exactly faces Earth’s, we’ve never really had an opportunity to view the Jovian poles before. Previous satellite missions have snapped photos, so we knew there were likely cyclones, but we didn’t have a lot of information about what size, what type, how persistent the storms were…

But Juno shows us incredible and bizarre storm systems. The Jovian north pole is one enormous cycle with a radius of 4000km, and it’s surrounded by a crown of eight more cyclones, each also around 4000km wide. Meanwhile, the Southern Polar Cyclone is surrounded by five other cyclones, each up to 7000km across.

From these observations, many questions arise. Two questions from the paper are ① Why are do the pentagon and octagon formations move so slowly? Between perijove orbits, the system appears to remain almost stationary. ② Why do the cyclones not merge at the poles? Saturn, for example, has just one cyclone at each pole. Why are these so stable in this configuration?

A final parting word: The paper concludes by discussing the tendency of these sorts of patterns to form due to 2D flow of fluids in a background of lower vorticity. These patterns are called “vortex crystals,” which is an extremely awesome phrase.