Jupiter’s Great Red Spot Has A Sibling
One of the most distinguishing features of Jupiter is its Great Red Spot, which is a storm raging on the surface, about twice the size of the Earth's diameter. However, it is not the only one that makes the beautiful features of the giant planet. Recently, a Great Cold Spot was discovered -- almost as large as the Great Red. It is responsible for the beautiful and vibrant auroras of Jupiter.
The Great Cold Spot was first detected by data from the Very Large Telescope in Chile and was found to stretch up to 15,000 by 7,500 miles across. Also, it is about 400 degrees Farenheiht cooler than the surrounding area in Jupiter's upper atmosphere.
Space.com noted that even though it disappears from time to time, it always forms again, offset from Jupiter's aurora. Tom Stallard, a planetary astronomer at the University of Leicester, said that the Great Cold Spot is much more volatile than the Great Red Spot. Moreover, it changes dramatically in shape and size over the course of a few days or weeks.
In a statement, the researchers said that the spot is likely formed as a byproduct of Jupiter's amazing auroras, especially considering that it always re-forms in a way that made them suspect it might be as old as the auroras themselves. The research revealed that aurora deposits energy into the Jupiter atmosphere, heating it so there is a difference between the top atmosphere and the one below. This then whips a sort of vortex that creates a patch that is cooler than the surroundings and offsets from the aurora itself.
EarthSky noted that the Great Cold Spot may have been created by the powerful energies on Jupiter's polar auroras. In addition, it can rival the scale of the Great Red Spot. Stallard said that there is a similar effect found in the Earth's own auroras, but a far less permanent fixture due to the variety of the auroras. Other than that, Jupiter's spin also acts as a form of trap that confines heat in place -- something that the Earth cannot do as well.