A stream of scientific analysis confirms that water once soaked Mars, raising the possibility of life there. Now, scientists say they may know where to look for it.

Advocates of manned space trips to Mars say it is only a matter of time before astronauts visit, and potentially colonize, the red planet.

It had enough force to blast a crater larger than 20 football fields. So where's the melted rock at this Arizona landmark? Now scientists say they know.

Space fans, get your telescopes ready. Tonight the Rosetta spacecraft will make a flyby of Earth on its way to launch the first probe to land on a comet.

Astronomers have detected unusual, powerful radio waves coming from an unknown source in the direction of the center of our galaxy.

Spaceships that vanish at the flick of a switch may be the stuff of science fiction, but new research suggests that objects really can be made to look invisible.

Don't let your eyes fool you—this new view is no painting. It's the best true-color image of the king of rings yet, NASA specialists say.

Martian pack ice is clearly visible for the first time, scientists say. It may be the best evidence yet of past seas, and it adds credence to the idea of life on Mars.

A new image of the outer reaches of the universe shows that galaxies formed clusters when the universe was only a billion years old, astronomers say.

Pluto was discovered 75 years ago this week and remains the only planet never visited by an Earth probe. Now a new NASA mission looks to change that.

A new image from NASA's Cassini spacecraft shows Saturn in eye-popping shades of blue—and striped with shadows of the planet's rings.

An astronomy conference is buzzing with announcements of possible diamond planets, pint-size solar systems, and the smallest known planet (so far).

Why do sunspot cycles, when plotted on a graph, look like butterfly wings? The answer could help predict solar storms, which can cause blackouts on Earth.

After plunging through the hazy atmosphere and landing on Titan early Friday morning, the Huygens space probe has transmitted dozens of images of Saturn's moon.

NASA engineers launched their Deep Impact spacecraft today. The missions aims to smash an 820-pound (370-kilogram) projectile into comet Tempel 1 on July 4, 2005.