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

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.

but it means it's not Planet Nine," Brown told Science. "I don't think this planet would have any of the effects on the solar system that we think we're seeing." But, if the researchers are right ...

"But I just don't see a way that the solar system can exist the way it does without there being a Planet 9." As this year progresses, he says, the Rubin observatory will start building up a ...

"The outer solar system is theoretically predicted to harbor an undiscovered planet, often referred to as Planet Nine," the researchers wrote in their paper. "However, no observational evidence ...

Brown analyzed the orbit of the candidate and concluded that its tilt—approximately 120 degrees from the Solar System's plane—deviates significantly from the predicted tilt for Planet Nine ...

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 ...

A new look through decades-old data has unveiled some of the most compelling evidence yet of a hidden ninth planet in the far reaches of our solar system, far beyond the bounds of Neptune and the ...

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.

Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system was touted more than a century ago.