Far beyond the bright planets, in the dim outskirts of the Solar System, astronomers keep stumbling on objects that refuse to ...

Mercury is the innermost and smallest of the eight major planets in our Solar System, orbiting closest to the Sun. Though ...

An illustration depicts what the surface of one of the exoplanets orbiting Barnard's Star may look like. The other three planets within the system can also be seen. - International Gemini ...

Astronomers have discovered a rare solar system with six planets moving in sync with one another. Estimated to be billions of years old, the formation 100 light-years away may help unravel some ...

(CNN) — Astronomers have discovered three previously unknown moons around Uranus and Neptune, the most distant planets in our solar system. (CNN) — Astronomers have discovered three previously unknown ...

Astronomers studying a disk of material circling a still-forming star inside our Galaxy have found a tantalizing result — the inner part of the disk is orbiting the protostar in the opposite direction ...

The Sun has a new neighbor that was hiding in plain twilight. An asteroid that orbits the Sun in just 113 days–the shortest known orbital period for an asteroid and second shortest for any object in ...

Eight planets, hundreds of moons, hundreds of thousands of asteroids, and billions of comets orbiting our Sun make up our ...

After decades of searching, astronomers may have finally stumbled upon the first moon known to exist beyond our solar ...

This discovery was made by two of NASA’s most celebrated telescopes. This illustration provided by Dan Durda shows the exoplanet Kepler-1625b with a hypothesized moon. On Thursday, Oct. 4, 2018, two ...