Mars

More than 30 years after NASA's Viking landers found no evidence for organic materials on Mars, scientists say a new experiment on Mars-like soil shows Viking did, in fact, hit pay dirt.

A manned mission to Mars may be decades away, but an international team of researchers will try to experience what one might be like by locking themselves up in a windowless capsule for a year-and-half — the time needed for a roundtrip to the red planet.

U.S. scientists say they have detected the first direct evidence of lightning occurring on Mars.