A ninth planet may exist beyond Neptune in the Kuiper Belt, a region populated by icy bodies that orbit the Sun.

After a decade-long search, some scientists say a growing number of clues point to the existence of a hidden planet in the ...

The search for Planet Nine, a hidden world beyond Neptune, is heating up as scientists prepare to use a powerful new telescope.

Scientists speculate if Planet Nine is a new planet or a primordial black hole. Discoveries could redefine our understanding ...

The solar system has nine planets, but in 2006 the International Astronomical Union declared Pluto a dwarf planet, making the ...

It’s often called Planet X or Planet Nine. “If we find another planet, that is a really big deal,” said Malena Rice, an assistant professor of astronomy at Yale University. “It could ...

This hypothetical Neptune-sized planet would circle our Sun on a highly elongated path, far beyond Pluto. It could have a ...

5️⃣ ‘Saddest thing’: When crews in Rome built a tiny temporary pool in front of the famous Trevi Fountain for tourists to ...

As NASCAR heads into its season finale, the series has also levied nine penalties for race manipulation in Martinsville.

Though fans never got to see the crew of the U.S.S. Discovery visit Risa, the pleasure planet was mentioned in two different episodes of Star Trek: Discovery. In the season 1 episode "Context Is For ...

While delivering remarks at the Earthshot Prize Awards on Wednesday, Nov. 6, Prince William spoke nine African languages as a sign of respect to a continent he has previously said “has always held a ...