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 ...

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

Researchers have found a candidate for the hypothetical Planet Nine, which could be an undiscovered giant planet way out in ...

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

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

A team of international scientists has identified a promising Planet Nine candidate by comparing infrared surveys of the sky ...

Astronomers may have found a candidate for Planet Nine. This planet is beyond Neptune. The finding could be the first ...

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 ...

Researchers for objects that moved slowly between IRAS and AKARI detections. IRAS and AKARI are far-infrared, all-sky surveys ...

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