Jupiter gets its stripe back

The South Equatorial Belt on Jupiter – which faded last spring from brown to white – now appears to be regaining its color.

One of Jupiter’s characteristic dark brown stripes – which amateur astronomers noticed last spring had faded in color from brown to white – now appears to be regaining its color.

Astronomers announced first-glimpse images – like the one at the top of this post – of the reappearing stripe Nov. 24.

The stripe, known as the South Equatorial Belt (SEB), is located just south of Jupiter’s equator and can be seen with amateur telescopes. It is usually brown, but last spring, it turned white. In early November, amateur astronomer Christopher Go of Cebu City in the Philippines observed a prominent bright spot in the unusually whitened belt – which astronomers are calling a “storm’ on Jupiter. This bright spot caused professional and amateur astronomers around the world to turn their telescopes toward Jupiter.

After follow-up observations with NASA’s Infrared Telescope Facility (IRTF), the 10-meter Keck telescope and the 8-meter Gemini telescope, all atop Mauna Kea in Hawaii, scientists now believe the stripe is making a comeback.

“The reason Jupiter seemed to ‘lose’ this band — camouflaging itself among the surrounding white bands — is that the usual downwelling winds that are dry and keep the region clear of clouds died down,” said Glenn Orton, a research scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “One of the things we were looking for in the infrared was evidence that the darker material appearing in visible light was actually the start of clearing in the cloud deck, and that is precisely what we saw.”

The image at the top of this post was taken on November 18 by the Gemini North Telescope. It combines blue, red and yellow images into a false-color composite that clearly shows the storm in the South Equatorial Belt. (Image Credit: JPL, University of Oxford, UC Berkeley, Gemini Observatory, University of San Carlos, Philippines)

This belt on Jupiter, which has been white since last spring, now appears to be turning dark again.

Source: UC Berkeley News

Deborah Byrd