Facts about Pluto, the dwarf planet in the Kuiper Belt ...

There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

It's been 20 years since Pluto was declassified as the ninth planet in our solar system, and many people wish it had never lost its status. A recent comment from NASA Administrator Jared Isaacman ...

See more of our trusted coverage when you search. Prefer Newsweek on Google to see more of our trusted coverage when you search. A team of astronomers believe they may have discovered a new dwarf ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

A recent research paper suggests that a planet may exist far beyond Neptune — less than 20 years after the previous ninth planet, Pluto, was demoted. That research paper, accepted last month for ...

There may soon be three new planets in our solar system. The expansion would be the result of a proposed new definition of what a planet is. The change is controversial, but if adopted by astronomy’s ...

The recent discovery of an enigmatic substance on the surfaces of both Titan, Saturn’s largest moon, and Pluto, our solar ...

Titan and Pluto sit at opposite ends of the solar system, one a giant moon wrapped in thick orange haze. The other is a ...