Planets

Pile up all of the human-made structures on the planet — from skyscrapers to cell phones — and it’d weigh in at approximately 30 trillion tons, according to a new study.

Behold! The European Space Agency's new Mars orbiter just sent back its first high-resolution images of the Red Planet, and the view is amazing.

A stunning new photo of Saturn's north pole spotlights the planet's bizarre hexagon-shaped vortex and beautiful bands of swirling winds.

Astronomers have discovered a large valley on Mercury that provides further evidence for the planet's shrinkage — an odd phenomenon that has been the topic of debate for decades.

The giant planet thought to be lurking unseen in the dark depths of the outer solar system may not stay hidden for much longer.

Simulated "Martian gardens" are helping NASA scientists learn which plants astronauts will be able to grow in future missions to the Red Planet.

The Rosetta probe drifted down to the surface of Comet 67P today (Sept. 30) and ended its 12-year mission.

The solar wind's evolution is finally coming to light, thanks to new analysis of observations from NASA's Solar Terrestrial Relations Observatory (STEREO).

A new app aims to change how you view time, by moving beyond hours, minutes and seconds to reveal your position in the cosmos and relate that position to the movement of celestial bodies.

A newly uncovered meteorite may be the first-ever extinct meteorite — a member of a class of meteorite that no longer falls to Earth.

Take that, Jupiter! The largest planet in the solar system just got whacked by an asteroid or a comet, and some intrepid stargazers have captured the planet's latest collision on camera.