There could be a ninth planet in our solar system that's lying in wait to be discovered - and no, it's not Pluto. Our solar ...

Mercury has long baffled astronomers because it defies much of what we know about planet formation. A new space mission ...

The giant planets weren't always where we find them today. Jupiter, Saturn, Uranus and Neptune formed in a more compact configuration and later underwent a violent reshuffling that scattered them to ...

By tracking tiny stellar wobbles, astronomers have detected planets forming around young stars for the first time.

CAPE CANAVERAL, Fla. (AP) — Astronomers have discovered the earliest seeds of rocky planets forming in the gas around a baby sun-like star, providing a precious peek into the dawn of our own solar ...

Astronomers are uncovering distant worlds beyond our solar system using ingenious indirect methods like observing stellar ...

CAPE CANAVERAL, Fla. — Astronomers have discovered a rare solar system in the Milky Way that boasts six planets orbiting in perfect rhythm like a cosmic orchestra, untouched by outside forces since ...

How common are Earth-like planets in the universe? When I started working on supernova explosions, I never imagined that my ...

This transcript was prepared by a transcription service. This version may not be in its final form and may be updated. Danny Lewis: Almost 800 million miles away from Earth, the moon Enceladus orbits ...

The International Astronomical Union (IAU) defines a planet as a celestial body orbiting the Sun, possessing sufficient mass for a nearly spherical shape, and having cleared its orbital neighborhood ...

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 ...