CT scans of fossil Hadrocodium skulls allowed scientists to reconstruct its brain. The olfactory bulbs, located at the front of the brain, grew steadily larger as millions of years passed. Matt Colbert/University of Texas at Austin hide caption

itoggle caption Matt Colbert/University of Texas at Austin

Geologists drop an acoustic transponder into the Pacific Ocean to measure movements on the seafloor. Courtesy of Japan Coast Guard hide caption

itoggle caption Courtesy of Japan Coast Guard

Protesters ride their bikes and hold flags reading "Nuclear power? No thanks" during a demonstration at the nuclear power plant of Biblis in Germany on April 25. Germany canceled plans to build new plants in the aftermath of the nuclear disaster in Japan. Thomas Lohnes/AP hide caption

itoggle caption Thomas Lohnes/AP

A technician checks a spot with a Geiger counter in a forest that burned in 1992. The wildfire released radioactive particles into the air that were deposited there during the 1986 nuclear accident at Chernobyl. Experts worry nearby forest, which is becoming overgrown, could again be ripe for a blaze. Patrick Landmann/Getty Images hide caption

itoggle caption Patrick Landmann/Getty Images

Phil Radford, executive director of Greenpeace USA, inspects oil-covered reeds while visiting the disaster site on May 20, 2010 south of Venice, Louisiana. A year after the spill, BP has yet to distribute $450 million dollars to scientists studying the disaster. John Moore/Getty Images hide caption

itoggle caption John Moore/Getty Images

This plant-eating dinosaur, Protoceratops andrewsi, was active day and night, like many other herbivorous dinosaurs. Researchers used measurements from the animal's eye socket to determine when it was most active. Courtesy Lars Schmitz hide caption

itoggle caption Courtesy Lars Schmitz

Dozens of spent fuel rod assemblies can be stored in dry casks, like the ones here at the James A. Fitzpatrick nuclear power plant in Scriba, N.Y. AP hide caption

itoggle caption AP

This shipping container was discovered upside down on the seafloor by researchers in June 2004, four months after it was lost at sea. Monterey Bay Aquarium Research Institute hide caption

itoggle caption Monterey Bay Aquarium Research Institute

Gray smoke rises from Unit No. 3 of the stricken Fukushima Dai-ichi nuclear plant Monday. Though no country is more familiar with nuclear peril than Japan, many Japanese don't connect the nuclear bombings of World War II with the ongoing crisis at Fukushima, says Yale-trained nuclear physicist Sukeyasu Yamamoto, who teaches in Tokyo. AP hide caption

itoggle caption AP

A fishing boat lies on its side in shallow water in the boat basin at Crescent City, Calif., after a tsunami surge withdrew March 11. The surges broke loose and damaged most of the 35 boats that remained in the harbor. Jeff Barnard/AP hide caption

itoggle caption Jeff Barnard/AP

Rising crude oil prices and improved extraction methods have made exploitation of Canada's oil sands more economical. Here, a view of an oil sands mine near Fort McMurray, Alberta. Mark Ralson/AFP/Getty Images hide caption

itoggle caption Mark Ralson/AFP/Getty Images

A production plant on the short of Mellitah, Libya, opened in 2004. Owned by Eni, the Italian oil and gas company, the facility is part of a pipeline that connects Libya to Sicily. Political unrest in the African nation is having effects in the worldwide oil market. Eni Press Office/AP hide caption

itoggle caption Eni Press Office/AP

Teeth from a cremated child were excavated from a site believed to be 11,500 years old. The color differences show uneven burning. The scale is in millimeters. Science/AAAS hide caption

itoggle caption Science/AAAS

Researchers aboard the Atlantis, a research vessel operated by the Woods Hole Oceanographic Institution, examine core samples brought up from the sea floor of the Gulf of Mexico by the deep-sea submersible Alvin on Nov. 24, 2010. The scientific community is conflicted about the lack of direction, coordination and funding in studying the aftermath of the Gulf of Mexico oil spill. Richard Harris/NPR hide caption

itoggle caption Richard Harris/NPR

A mature Atlantic tomcod collected from the Hudson River. These tomcod evolved to handle excessive amounts of industrial pollutants, like PCBs and dioxin, in the water. Science/AAAS hide caption

itoggle caption Science/AAAS