A strange world just 47 light-years from Earth is rewriting what scientists thought they knew about alien planets. Hidden ...

Two cosmic collisions near the star Fomalhaut solve the mystery of a disappearing "planet" and show rare planetesimal crashes ...

Scientists watching the nearby Fomalhaut star system have directly seen two protoplanets smash together for the first time.

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 ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth than the hypothetical Planet X, which astronomers have been hunting for ...

LONDON — The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper's authors have ...

Our solar system is a smashing success. A new study suggests that from its earliest period — even before the last of its nebular gas had been consumed — Earth’s solar system and its planets looked ...

The number of confirmed planets outside of our solar system—known as exoplanets—has risen to 6,000, NASA has said. There is huge variety across these distant worlds, the space agency says, with ...

More than 2 billion kilometers farther from the sun than Pluto, a frigid world named Makemake sports the most distant gas ever seen in our solar system, new observations reveal. “By surprise, we found ...

Just decades after the first exoplanets were identified, our database of the distant worlds—monitored by the NASA Exoplanet Science Institute—has breached a new threshold. Now, astronomers have ...