Talk of the Nation

The Mars Phoenix is scheduled to touch down on the Red Planet on Sunday. It will land in an arctic plane and then hunt for frozen water and possibly for signs of life. The Phoenix incorporates some of the experiments and technologies that were originally scheduled to fly on previous, failed missions.

Computer logic usually consists of electronic switches, but recently, scientists have been exploring alternative means for conducting calculations. Scientists report that they have created specially-modified E. coli bacteria capable of performing a specific type of calculation.

Indiana Jones is back on the big screen with Indiana Jones and the Kingdom of the Crystal Skull. But what exactly is a "crystal skull"? Archaeologist Jane McLaren Walsh explains.

It is well known that many organisms have a "circadian clock" — a biological time-keeping mechanism that connects the body's rhythms to external light levels. Now, researchers have found a second internal clock connected to food consumption that can overrule the regular light-based clock.

Astronomers who happened to be observing in the right place at the right time recently collected new pieces of data that allow them to paint an unprecedented picture of what goes on during the initial stages of an ultra-powerful stellar explosion.

Tiny tubes made of carbon atoms have been among the main ingredients of the nanotech revolution. But researchers have found that when injected into mice, nanotubes could behave in a way similar to the way asbestos fibers behave, forming lesions that lead to cancer.