Second 'Great Spot' found on Jupiter
Another 'Great Spot' has been found on Jupiter.
Scientists reported yesterday that the dark expanse is 24,000km across and 12,000km wide. It's in the upper atmosphere and much cooler than the hot surroundings, thus the name Great Cold Spot. Unlike the planet's familiar Great Red Spot, this newly discovered weather system is continually changing shape and size. It's formed by the energy from Jupiter's polar auroras.
A team used a telescope in Chile to chart the temperature and density of Jupiter's atmosphere. When the researchers compared the data with thousands of images taken in years past by a telescope in Hawaii, the Great Cold Spot stood out. It could be thousands of years old.
"The Great Cold Spot is much more volatile than the slowly changing Great Red Spot... but it has reappeared for as long as we have data to search for it, for over 15 years," the University of Leicester's Tom Stallard, lead author of the study, said.
Mr Stallard said Jupiter's upper atmosphere may hold other features. Scientists will be on the lookout for them while also studying the Great Cold Spot in greater detail, using ground telescopes as well as NASA's Juno spacecraft in orbit around Jupiter, he said.