A National Science Foundation artist's drawing shows the inner four planets orbiting Gliese 581, a red dwarf star just 20 light-years from Earth. The newly discovered planet, in the foreground, has a 37-day orbit and, like Earth, is distant enough from the star for liquid water to exist. Lynette Cook hide caption

itoggle caption Lynette Cook

Inside Veolia Energy's Plant Three in Baltimore, blue pipes carry chilled water that will be sent out to cool nearby buildings. The green pipes carry condensed water that removes heat from the chilling system, and orange pipes carry a refrigerant. The yellow pipes are for a future cooling system. Mike Ruocco/NPR hide caption

itoggle caption Mike Ruocco/NPR

Sheldon Cooper — a character played by Jim Parsons in CBS's The Big Bang Theory has an IQ of 187 and several advanced degrees but often has trouble with social interactions with other people. CBS hide caption

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Retired Coast Guard Adm. Thad Allen testifies Monday before the commission investigating the Gulf of Mexico oil spill. Though Allen was the government's leader of the spill response, he acknowledged it was not always clear to the public who was in charge. Mark Wilson/Getty Images hide caption

itoggle caption Mark Wilson/Getty Images

A slice of Hurricane Karl was captured by NASA's CloudSat satellite. The clouds were just over 8 miles high. hide caption

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During a raid on a Missouri dogfighting ring, Tim Rickey of the ASPCA holds Dharma, a pit bull who lost part of her leg in a fight. Courtesy of the Humane Society of Missouri hide caption

itoggle caption Courtesy of the Humane Society of Missouri