A replica of the pinky bone fragment found in a Siberian cave. Researchers used the bone bit to extract and sequence the genome of a girl who lived tens of thousands of years ago. Max Planck Institute for Evolutionary Anthropology hide caption

itoggle caption Max Planck Institute for Evolutionary Anthropology

Roger Angel, an astronomer at the University of Arizona, stands in front of his new project: a solar tracker. Angel wants to use the device to harness Arizona's abundant sunlight and turn it into usable energy. Jason Millstein for NPR hide caption

itoggle caption Jason Millstein for NPR

In this photo released by SkyandTelescope.com, a Perseid meteor flashes across the constellation Andromeda on Aug. 12, 1997. Rick Scott and Joe Orman/AP hide caption

itoggle caption Rick Scott and Joe Orman/AP

Adam Steltzner, the leader of the rover's entry, descent and landing engineering team, cheers after Curiosity touched down safely on Mars on Sunday. Bill Ingalls/NASA/Getty Images hide caption

itoggle caption Bill Ingalls/NASA/Getty Images

An artist's concept of NASA's Mars Science Laboratory spacecraft depicts the final minute before the rover, Curiosity, touches down on the surface of Mars. NASA/JPL-Caltech hide caption

itoggle caption NASA/JPL-Caltech

NASA engineer Adam Steltzner led the team that designed a crazy new approach to landing on Mars. Rachael Porter for NPR hide caption

itoggle caption Rachael Porter for NPR

United States runner Kam Conley sheds layers to train for the Olympics in England on Monday. Less clothing means more evaporation, keeping athletes cooler. Hussein Malla/AP hide caption

itoggle caption Hussein Malla/AP

Joe Palca serves up some hot tea on a very hot day at Teaism in Washington, D.C., last week. Maggie Starbard/NPR hide caption

itoggle caption Maggie Starbard/NPR