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

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 ...

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.

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

A team of astronomers poring through old astronomical data may have seen a candidate for the elusive Planet Nine – a ...