Planets

The gassy world is "darker than charcoal" and may swallow up to 99 percent of the light its local star sheds upon it.

The upper cloud tops of Uranus are shot through with hydrogen sulfide, the gas that smells of rotten eggs.

The lost planet was the size of Mercury or perhaps Mars, researchers now say.

The space travel of science fiction could be closer than you think.

One of Stephen Hawking’s final television projects was the documentary "Leaving Earth," airing March 25.

Long ago, Earth was an unformed doughnut of molten rock called a synestia, and the moon was part of its filling.

Supermassive black holes near the center of our Milky Way galaxy may have transformed "mini-Neptune" exoplanets into rocky "super-Earths," new research shows.

The flat-Earth rocketeer remains planet-bound.

These dusty comets, speeding through distance space, are the smallest objects ever detected in another star system.

The "Doomsday Clock," a hypothetical countdown to global Armageddon, gets a new position.

Last year was one of the three warmest years on record, according to a new report by NASA and NOAA.

While it looks like an asteroid, the first interstellar object spotted passing through the solar system, called 'Oumuamua, may be more like a comet in disguise.

Data gathered by satellites circling Earth since 1997 come together in a breathtaking time lapse of our dynamic planet.

Mounting evidence suggests it's hard to imagine our solar system without the unseen world dubbed Planet Nine.

NASA's Cassini spacecraft broke up in Saturn's atmosphere this morning, bringing an end to its historic 13-year mission at the ringed planet that was marked by incredible discoveries.

Saturn's rings are one of the most compelling features of the solar system.

In a new experiment, researchers have created a super-dense version of ice found deep within icy moons and colliding comets, and watched it form in nanoseconds.