Scientists have long anguished over how little is known about Mercury, the innermost of the four terrestrial planetary bodies in our solar system.

The first thing an alien race is likely to hear from Earth is chirps and whistles.

NASA spacecraft observations reveal what appears to be by far the largest impact crater ever found in the solar system.

Imagine landing on the Moon, climbing down the ladder of your spacecraft, and looking around the harsh lunar landscape—to see another, older spacecraft standing only 200 yards away.

The biggest black holes may feed just like the smallest ones, according to data from NASA's Chandra X-ray Observatory and ground-based telescopes. This discovery supports the implication of Einstein's relativity theory that black holes of all sizes have similar properties, and will be useful for predicting the properties of a conjectured new class of black holes.

It was expensive lesson but "Gravity Probe B" was not a failure - NASA and science simply learned there is no "frame-dragging" or "space-time fabric" and Einstein's General Theory has another weakspot (his "Principle of Equivalence" is the big one).

New observations from NASA's Phoenix Mars Lander provide the most magnified view ever seen of Martian soil, showing particles clumping together even at the smallest visible scale.

Scientists have confirmed for the first time that an important component of early genetic material which has been found in meteorite fragments is extraterrestrial in origin.

NASA has awarded a contract to Oceaneering International Inc. of Houston, for the design, development and production of a new spacesuit system. The spacesuit will protect astronauts during Constellation Program voyages to the International Space Station and, by 2020, the surface of the moon.

NASA's Phoenix Mars Lander has filled its first oven with Martian soil. "We have an oven full," Phoenix co-investigator Bill Boynton of the University of Arizona, Tucson, said today. "It took 10 seconds to fill the oven. The ground moved."