Two storms merge in Saturn's gaseous atmosphere in a series of images taken by the Cassini spacecraft, which is due to arrive at the ringed planet July 1
Two storms merge in Saturn's gaseous atmosphere in a series of images taken by the Cassini spacecraft, which is due to arrive at the ringed planet July 1.
Each storm was some 620 miles (1,000 kilometers) wide, appearing as spots in
the southern hemisphere. They merged March 19-20. The pictures, taken between
Feb. 22 and March 22 and processed to enhance contrast, were released yesterday.
See a larger version of the set here.
Storms on Earth can merge, but it is much more common for them to fade away after days or, with hurricanes, a week or two. On Saturn and the other giant planets, storms last for months or years. Jupiter's Great Red Spot has raged for centuries. Instead of simply fading away, many storms on the giant planets end their lives by merging.
The northernmost of the two storms moves westward at a slightly greater rate than the southern one. The storms drift with broader atmospheric currents and engage in a counterclockwise dance before getting together.
Just after the merger, the new feature is elongated in the north-south direction, with bright clouds on either end. Two days later, on March 22, it has settled into a more circular shape and the bright clouds have spread around the circumference to form a halo. Whether the bright clouds are particles of a different composition or particles at a different altitude is uncertain, astronomers said.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.
Credit: NASA/JPL/Space Science Institute
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