A satellite captured the erupting of the Okmok Caldera volcano on Umnak Island in Alaska in July 2008. The volcano spewed both steam and ash. NASA/AP hide caption

itoggle caption NASA/AP

This infrared image shows ash spewing out of Iceland's Eyjafjallajokull volcano. It was taken April 17 by a NASA spacecraft. Hotter areas, shown in red, can be seen at the ash plume's base. NASA/JPL/EO-1 Mission/GSFC/Ashley Davies hide caption

itoggle caption NASA/JPL/EO-1 Mission/GSFC/Ashley Davies

The MODIS instrument on NASA's Terra satellite captured an ash plume from the Eyjafjallajokull volcano on Friday. Though satellite images can tell scientists where the ash is, they don't help forecasters determine how much ash is in the air — or at what point it becomes a hazard to airplanes. MODIS Rapid Response Team/NASA via Getty Images hide caption

itoggle caption MODIS Rapid Response Team/NASA via Getty Images

Smoke and steam hang over the Eyjafjallajokull volcano in Iceland that erupted for the second time in less than a month. The eruption melted ice, shot smoke and steam into the air and forced hundreds of people to flee rising floodwaters. Jon Gustafsson/AP hide caption

itoggle caption Jon Gustafsson/AP

Nowadays most corn is genetically engineered or modified, like this Bt-corn being loaded near Rockton, Ill. Scott Olson/Getty Images hide caption

itoggle caption Scott Olson/Getty Images

Gas centrifuges used to produce enriched uranium sit in a plant in Piketon, Ohio, in 1984. The technology for laser-based enrichment is much smaller than technology using centrifuges, and would be easier to secretly develop for weapon production. Wikimedia Commons hide caption

itoggle caption Wikimedia Commons

At Oak Ridge National Laboratory, an employee works with a mechanical arm to manipulate items inside the radioactive hot cell. The hot cells are used to manufacture new reactor fuel made from spent nuclear waste. Courtesy of Oak Ridge National Laboratory hide caption

itoggle caption Courtesy of Oak Ridge National Laboratory

Scientists at the Large Hadron Collider near Geneva celebrate after the particle accelerator started smashing protons at record energies earlier today. Fabrice Coffrini/AFP/Getty Images hide caption

itoggle caption Fabrice Coffrini/AFP/Getty Images