New images unlock secrets on Uranus

Images of Uranus yielding new details of the planet and its atmosphere are changing its reputation as the bore of the solar system, U.S. astronomers say. In 1986, when the Voyager spacecraft swept past Uranus, the probe sent back images of the planet that were "notoriously bland," they said, but a new technique applied at the Keck Observatory in Hawaii has revealed a raft of new details about the planet's enigmatic atmosphere. Large weather systems behave in bizarre ways on Uranus, reports Larry Sromovsky, a University of Wisconsin-Madison planetary scientist who led the new study using the Keck II telescope. The planet's deep blue-green atmosphere is thick with hydrogen, helium and methane, and winds blow mainly east to west at speeds up to 560 mph, the researchers said. "Some of these weather systems," Sromovsky said, "stay at fixed latitudes and undergo large variations in activity. Others are seen to drift toward the planet's equator while undergoing great changes in size and shape." The researchers used new infrared techniques to detect smaller, more widely distributed weather features to trace the planet's pattern of blustery winds. "We're seeing some new things that before were buried in the noise [in the data]," Sromovsky said. The new Keck pictures of the planet are the "most richly detailed views of Uranus yet obtained by any instrument on any observatory," he said.