A first-of its-kind space weather "tabletop" exercise has revealed major weaknesses in America's preparedness for severe ...

Quasars represent some of the most luminous and energetic phenomena in the universe. These distant powerhouses are driven by ...

A team of astronomers believes they may have spotted a serious candidate for a ninth planet in our Solar System. This object, ...

The Keck Observatory and NASA’s Hubble Space Telescope may have uncovered a "potential three-body system in the Kuiper Belt," ...

From solar probes to deep space missions, these record-breaking human-made objects reached speeds that make bullets and jets ...

To understand how chaotic the early solar system was, we need only gaze at the moon. Its cratered surface bears the scars of ...

A ninth planet the size of Neptune may be hidden in the far reaches of the solar system, but the evidence has left some experts skeptical.

Discovered in 1930, Pluto was long considered our Solar System's ninth planet, but was unseated in 2006 after the discovery ...

NASA’s Juno mission has gathered new findings after peering below Jupiter’s cloud-covered atmosphere and the surface of its ...

Researchers say they found a curious dot on infrared images taken 23 years apart that seems to be moving in a manner consistent with a large, distant planet.

An alternate explanation that fits the evidence is that Vesta was once part of a planet – but which planet that might been ...

Astronomers have long speculated about an unseen planet lurking in the solar system's outer edge. This hypothetical world, ...