Jupiter's Red Spot Isn't What We Thought It Was
Researchers re-create phenomenon in lab
By Matt Cantor,  Newser User
Posted Nov 12, 2014 8:43 AM CST
This undated composite handout image provided by NASA, taken by the Hubble Space Telescope, shows the Great Red Spot in 2014, left; in 1995, top right; 2009, center right; and 2014, bottom right.   (AP Photo/NASA)

(Newser) – Scientists have made their own version of Jupiter's Great Red Spot in a lab, and it suggests that the spot's cause is very different from what's been postulated. An existing theory holds that the spot is the result of chemicals underneath the planet's clouds. But following the new research, experts say that the sun is responsible for the color: Sunlight may break up chemicals in Jupiter's atmosphere, Phys.org reports. Scientists in Pasadena, Calif., came to the conclusion after re-creating the effects at NASA's Jet Propulsion Laboratory.

They were able to get a Spot-like red effect by directing ultraviolet light at ammonia and acetylene, gases that are both found on the planet. Their new theory: "Most of the Great Red Spot is actually pretty bland in color, beneath the upper cloud layer of reddish material," says a researcher. "Under the reddish 'sunburn' the clouds are probably whitish or grayish." So why is it confined to just one spot? "The Great Red Spot … reaches much higher altitudes than clouds elsewhere on Jupiter," the expert notes. The Spot is actually a storm with winds of up to hundreds of miles per hour, the Daily Mail reports. Wind in the area brings ammonia particles higher in the atmosphere where they can be exposed to more sunlight, and a vortex keeps them there, the researchers say. The Spot, by the way, is a lot smaller than it used to be.