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

Scientists examined infrared space surveys to narrow down candidates for Planet 9. Planet 9 would be so far from the Sun that ...

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 ...

If the object really is Planet Nine, it would be larger than Neptune and exist 700 times further from the sun than Earth.

Using two infrared space telescopes and a 23-year gap, scientists may have spotted a mysterious, slow-moving object beyond ...

The presence of another planet in the solar system could explain the odd movements of some of the bodies in the Kuiper Belt.

The solar system consists of our star, the sun, and everything bound to it by gravity: the planets Mercury, Venus, Earth, ...

A new look through decades-old data has unveiled some of the most compelling evidence yet of a hidden ninth planet in the far ...

Astronomers have detected a promising sign of a ninth planet lurking at the the farthest reaches of the Solar System.

A powerful new observatory is the best hope yet for finding the elusive Planet 9, a large planet that some scientists say is hidden in our solar system.

Planet Nine (or Planet X as NASA calls it) first emerged as a real possibility in 2016, when two astronomers from the California Institute of Technology presented evidence of a large gravitational ...

For about a decade, he and other researchers have been trying to prove that the so-called "Planet 9" exists. So far, the only evidence has come from some oddities in the orbits of small Pluto-like ...