The main ring of the Tevatron, seen in a time exposure. For a quarter century, the particle accelerator at a lab outside Chicago was the most powerful machine of its kind in the world. Reidar Hahn/Fermilab hide caption

itoggle caption Reidar Hahn/Fermilab

This picture of the Eros asteroid is the first of an asteroid taken from an orbiting spacecraft. The crater at the center is about 4 miles across. JPL/JHUAPL/NASA hide caption

itoggle caption JPL/JHUAPL/NASA

Officials from Arizona-based First Solar and a New Mexico power company gather after the dedication of a new solar array in Albuquerque in April. Susan Montoya Bryan/AP hide caption

itoggle caption Susan Montoya Bryan/AP

Water plant operator Torrey Jones checks the clarity of a sample of treated water at the Beaver Falls Municipal Authority water treatment plant in Beaver Falls, Pa. Keith Srakocic/AP hide caption

itoggle caption Keith Srakocic/AP

This small juvenile skunk was caught by Des Plaines, Ill., homeowner Richard Kaulback. He says there have always been raccoons and opossums in the Chicago area, but this year, skunks have become prolific. Cheryl Corley/NPR hide caption

itoggle caption Cheryl Corley/NPR