[petuniasevan]

That's a Dark Spot all right; I can't see anything but black there.

Wait a minute. My bad. THERE'S the Dark Spot, to the upper left of the polar region's dataless central region!

Here's the source movie as thumbnail; click on the image for the full-size GIF movie.

UV movie of polar Jupiter

WARNING! The full-size GIF is big! That's not so much in dimensions (512 square) but in file size. It's about 26 MB so slow Internet connections may be overwhelmed. It's worth a short wait for the great visual impact.

[petuniasevan]

[GodBlessRonaldReagan]

Great pic! I will certainly miss APOD if it goes on hiatus for the war...

[mikrofon]

Darn, those lipstick marks don't seem to want to go away ;^)

Great catch, as always .... will also miss APOD, but if needs be, let's roll!

[RightWhale]

This spot is a migrating resonance in the jet stream. The jet stream is a kind of standing wave induced by the various atmospheric forces and insolation. The speed of moving air inside the jet stream is higher than the general atmospheric rotation, which is faster than the planetary rotation. Since the standing wave lacks perfect resonance around the planet, there is an instability, a partial resonant peak that continually migrates in search of the next higher resonant number. Thus, if the resonant wave has four peaks, the partial peak would be the fifth, except that it can't settle into one location since it is somewhat away from being in tune. Call it a wolf note or a discord in the jet stream.