Almost 20 years after Pluto was infamously downgraded from its status as a planet, scientists now believe they have discovered a new planet in our solar system.

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 ...

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.

The existence of Planet Nine — or any other undiscovered ninth planet in our solar system — will likely remain a contentious subject for now. However, 2025 could prove to be the beginning of ...

For over a century, astronomers have wondered if there's an extra planet in our Solar System that we haven't been able to detect yet. It seems like we get another "Planet Nine" candidate ...

The planet is about 10% larger than Jupiter, but much hotter because it is 13 times closer to its star than Mercury is to our sun. HD 189733b only takes about two Earth days to complete a single ...

This week presents a unique chance to see all of the seven other planets in our solar system in the sky at the same time. "What an opportunity to get outside, spend some time with your family, out ...