So the vortex, which was first seen in the ice giant’s mid-southern latitudes, is not going out with this expected bang, and is instead slowly fading away into oblivion. Its fate may have something to do with the unexpected direction of its drift. Neptune’s gigantic fart is currently moving very slowly in a southerly direction, traversing a distance of about 1.7 degrees to 2.5 degrees of latitude each year. Unlike Jupiter’s Great Red Spot, which is kept in place by broad jet streams, Neptune features just three broad streams—one that blows westward at the equator, and a pair that blows in an eastward at the poles. This allows Neptune’s vortex to be a shiftless drifter, changing its “traffic lanes” in ways that are difficult to anticipate.


The latest study shows that Neptune’s vortices are highly variable, transient, and recurring features; they’re like snowflakes, similar but not exactly the same. The astronomers will continue to monitor the vortex with Hubble, and we’ll see where it goes from here—and if and when a new dark spot appears.

[Astronomical Journal]