While Hiding Behind the Sun, Jupiter Loses One of its Belts

Jupiter, Before and After

Anthony Wesley

The science world is upside down this afternoon. First North Korea announces it has cracked the nut on nuclear fusion. Now Jupiter has lost one of its belts, specifically the Southern Equatorial Belt (SEB) which figures prominently in Jupiter's overall appearance.

Astronomers aren't exactly sure why this happens, but the flightiness of the SEB is actually not unprecedented. Jupiter's bands are actually clouds, with the SEB being primarily made up of ammonia ice, sulfur, and phosphorous hovering above the planet's toxic, gaseous surface. The belt took leaves of absence in both the early 1990s and in 1973, so its disappearance now, if anything, is a bit overdue (it seems to be on a roughly 15-year cycle).

But due to the orbital dynamics of Earth and Jupiter, this particular disrobing was far more abrupt. Jupiter has been hanging out on the other side of the sun since late 2009, obscured from our view for the last few months. The belt disappeared while Jupiter was hiding, making for quite a drastic change in appearance when it recently re-emerged.

If this occurrence follows the precedent of the others, the planet should maintain its appearance for another few weeks – possibly even months – at which point a bright white spot will appear and begin seeding the former belt with dark blobs, eventually restoring the SEB to its former dark color. And if that doesn't happen? Well, that's not really a problem. Jupiter has looked more or less the same as long as we've known her, so if she wants to shake things up a bit, that's her prerogative.

For kicks, we've include the original footage from the Voyager flyby below, where you can get a good look at just how lively Jupiter's atmosphere can be.