A new study, however, identifies a possible candidate. A separate team of astronomers compared 1983 data from the Infrared ...

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

For years, astronomers have toyed with the idea that the Sun hides an extra planet so distant and dim that even the best ...

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

Over millions of years, these objects grew larger, sweeping up material in their orbits and becoming the planets we know today. This model of solar system formation is known as the nebular hypothesis.

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.

Researchers have found a candidate for the hypothetical Planet Nine, which could be an undiscovered giant planet way out in our solar system. However, as with all ninth planet research, the new ...

While scientists are still trying to confirm Planet Nine's existence, NASA says proving that this ice giant is real would help astronomers explain several mysteries within our solar system.

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 ...

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 ...