Washington, May 23 : Astronomers have detected the presence of a third red spot on Jupiter, which has appeared alongside the Great Red Spot and Red Spot Jr. in the turbulent Jovian atmosphere.
This third red spot, which is a fraction of the size of the two other features, lies to the west of the Great Red Spot in the same latitude band of clouds.
The new red spot was previously a white oval-shaped storm. The change to a red color indicates its swirling storm clouds are rising to heights like the clouds of the Great Red Spot.
One possible explanation for this is that the red storm is so powerful that it dredges material from deep beneath Jupiter's cloud tops and lifts it to higher altitudes, where solar ultraviolet radiation, via some unknown chemical reaction-produces the familiar brick color.
Detailed analysis of the visible-light images taken by Hubble's Wide Field Planetary Camera 2 on May 9 and 10, and near-infrared adaptive optics images taken by the W.M. Keck telescope on May 11, is revealing the relative altitudes of the cloud tops of the three red ovals.
Because all three oval storms are bright in near-infrared light, they must be towering above the methane in Jupiter's atmosphere, which absorbs the Sun's infrared light and so looks dark in infrared images.
Turbulence and storms first observed on Jupiter more than two years ago are still raging, as revealed in the latest pictures.
The Hubble and Keck images also reveal the change from a rather bland, quiescent band surrounding the Great Red Spot just over a year ago to one of incredible turbulence on both sides of the spot.
Though Red Spot Jr. appeared in the spring of 2006, the Great Red Spot has persisted for as long as 200 to 350 years, based on early telescopic observations.
If the new red spot and the Great Red Spot continue on their courses, they will encounter each other in August, and the small oval will either be absorbed or repelled from the Great Red Spot.