The Great Red Sunburn

Jupiter has one of the largest planetary atmospheres in the solar system, with three atmosphere layers made up of ammonia, ammonium hydrosulfide and water clouds at different altitudes.   As chaotic and beautiful Jupiter's atmosphere is, the great red spot out-shines them all.

The Great Red Spot is a vortex the size of three Earths.  Researchers have been theorising for hundreds of years as to the cause of the Great Red Spot's color. Up until recently it was thought that the color was some kind of red phosphorus or sulfur compound rising from beneath Jupiter's clouds.

Scientists at Nasa's JPL have been studying data gained from Nasa's Cassini spacecraft, which flew by Jupiter in December 2000 on its way to Saturn and its moons.  They also conducted laboratory experiments  by blasting ammonia and acetylene gases (chemicals known to exist in Jupiter's atmosphere) with ultraviolet light, in order to simulate how the sun affects these chemicals.  The experiment produced a reddish material that matched a model of the Great Red Spot where the red-colored material had been confined to the uppermost reaches of the vortex.

"Our models suggest most of the Great Red Spot is actually pretty bland in color, beneath the upper cloud layer of reddish material," said Kevin Baines, a Cassini team scientist from JPL. "Under the reddish 'sunburn' the clouds are probably whitish or greyish."

Read more in the article on International Business Time site