Astronomers have discovered icy rocks in the outer solar system that challenge the known laws of physics, suggesting the ...

Astronomers have spotted an intriguing cluster of objects in the Kuiper belt, an enormous, donut-shaped region of icy objects beyond Neptune.

Most astronomers agree there are only four terrestrial, or rocky, planets in our solar system, all of which lie close to the sun. But new research suggests that up to five more may be lurking at the ...

The outer planets of the solar system are swarmed by ice-wrapped moons. Some of these, such as Saturn's moon Enceladus, are ...

Theia, the world that helped form the Moon, came from the Solar System. Chemical clues in Earth and Moon rocks reveal this ...

The outer planets of the Solar System are swarmed by ice-wrapped moons. Some of these, such as Saturn’s moon Enceladus, are ...

Nearly a century after Pluto’s discovery, astronomers are still hunting for mysterious planets beyond Neptune - including a ...

Roughly four and a half billion years ago the planet Theia slammed into Earth, destroying Theia, melting large fractions of Earth’s mantle and ejecting a huge debris disk that later formed the moon.

In the remote outer reaches of planetary systems, far beyond the orbit of known planets, enormous and mysterious worlds silently loop around their stars. Some drift as far as 10,000 times the distance ...

EVANSTON, Ill. — Except for the fact that we call it home, for centuries astronomers didn’t have any particular reason to believe that our solar system was anything special in the universe. But, ...