Penetrator bombs, commonly known as bunker busters, are stored on pallets at an ammunition plant in McAlester, Okla., in 2002. The U.S. sold 55 bunker busters to Israel in 2009, according to a recent Newsweek report. Sue Ogrocki/AP hide caption

itoggle caption Sue Ogrocki/AP

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

Kansas Secretary of State Kris Kobach says the Sept. 11, 2001, terrorist attacks energized him around the issue of illegal immigration. "We discovered that five of the 19 hijackers had been in the country illegally," Kobach says. Ed Zurga/AP hide caption

itoggle caption Ed Zurga/AP

Ryan Witmer (left) and Jhonmar Castillo wait with other couples to exchange vows in a civil union ceremony June 2 in Chicago's Millennium Park. New data from the U.S. census may reveal as much about changing attitudes as about changing numbers. Scott Olson/Getty Images hide caption

itoggle caption Scott Olson/Getty Images