Here's a mildly reassuring fact from today's AAAS news briefing on nuclear forensics: There are no known cases of a finished nuclear weapon being stolen or sold on the black market. But raw nuclear materials are a different story. In the past fifteen years, more than 1,300 cases of nuclear trafficking have been registered. Anita Nilsson of the International Atomic Energy Agency, a member of today's panel, said that most of these cases were "innocent," but some are anything but. The 400 grams of weapons-ready plutonium seized at the Munich airport in 1994?

The future of secure travel hinges on seamless, instant communication—and 24/7 autonomous surveillance. For a look at the technologies that will soon safeguard your travel plans, launch the photo gallery.

In a word: no. It would be impossible to destroy the Red Planet with any device scientists can build, let alone finance. Planets can survive enormous assaults; the Hellas Basin, a Martian crater about 1,300 miles wide, testifies to the planet having once collided with an asteroid so massive that the impact generated well over a hundred million megatons of energy. If a meteoroid that size were to hit Earth, it could wipe out life on an entire continent.

According to the U.S. Department of Defense, hundreds of
underground bunkers in enemy territories serve as weapons silos, command
centers and safe havens for rogue leaders. Drilled several hundred feet or deeper into the ground, many of the hideouts are far beyond the reach of conventional weapons. The Pentagon’s solution: Build a super-slim bomb called a Robust Nuclear Earth Penetrator (RNEP) capable of piercing 20 feet of solid rock and unleashing shock waves on par with a magnitude-7 earthquake.

This fall Congress will decide whether to approve $8.5 million to complete a

It's a slow-motion horror movie: Nuclear waste leaks from underground storage shafts and seeps toward a river, where it contaminates drinking water used by millions of people. That's exactly the scenario unfolding at the Hanford Nuclear Reservation in rural Washington State.

The solution, too, sounds like a page ripped from a Hollywood screenplay: Insert two industrial-strength electrodes deep into the ground, and melt the soil—along with everything around it—into solid glass, trapping the toxic waste for thousands of years.

The U.S.