The open pit mine at Molycorp Minerals' rare earths mining and processing facility in Mountain Pass, Calif. The mine is expected to produce 40,000 tons of rare earth minerals each year after a $500 million expansion project. Courtesy of Molycorp Minerals hide caption

itoggle caption Courtesy of Molycorp Minerals

At the Cleveland Clinic, technician Larry Raber and physician Mei Lu practice the ultrasound technique to measure CCSVI in patients with MS on medical student Claudiu Diaconu. Cleveland Clinic Center for Medical Art & Photography hide caption

itoggle caption Cleveland Clinic Center for Medical Art & Photography

The SpaceX Falcon 9, carrying a Dragon capsule, lifts off the launch pad at Launch Complex 40 at Cape Canaveral on Dec. 8, 2010. NASA hide caption

itoggle caption NASA

These primitive tools were found on the eastern edge of the Arabian Peninsula, outside the range of Neanderthals. Researchers say humans may have left Africa earlier than previously thought, crossing what is now the bottom of the Red Sea. Science/AAAS hide caption

itoggle caption Science/AAAS

Las Vegas police stand guard outside Harrah's hotel-casino in Las Vegas on Feb. 21, 2006. As officer Norman Jahn recalls, police arrested the suspected gunman without firing a shot. Jae C. Hong/AP hide caption

itoggle caption Jae C. Hong/AP