This week, an old astronomical controversy is renewed as researchers present new evidence for a hidden "Planet X" in our solar system.

Researchers say they found a curious dot on infrared images taken 23 years apart that seems to be moving in a manner ...

Legendary actor William Shatner wants President Trump to restore Pluto to greatness as scientists claim to have found a “new” ...

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 ...

A ninth planet the size of Neptune may be hidden in the far reaches of the solar system, but the evidence has left some experts skeptical.

Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, ...

Today, it’s believed that Jupiter and Saturn, the largest planets, were the first to fully form, both within a few million years. Uranus and Neptune were next, within 10 million years. The inner ...

Astronomers believe that our solar system may still hold surprises, with ongoing efforts to find a hidden ninth planet, often referred to as Planet Nine or Planet X. If confirmed, this discovery ...

Astronomers claim to have discovered a new ninth planet in our Solar System. Planet Nine, also known as Planet X, is a hypothetical celestial object that would distantly orbit our Sun – but ...

Stars that pass close to the solar system could pull planets out of alignment, sending them hurtling into the sun or out into ...

"How planets are born is an unsolved area of research," astrophysicist Daniel Price of Australia's Monash University told ...