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

Caroline Delbert is a writer, avid reader, and contributing editor at Pop Mech. She's also an enthusiast of just about ...

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.

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

An object seen to have moved in the time between when it was imaged by the IRAS and AKARI surveys in 1983 and 2006 ...

Astronomers have long speculated about an unseen planet lurking in the solar system's outer edge. This hypothetical world, ...

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

Discover the mystery of Planet Nine, the elusive celestial body beyond Neptune. Explore the latest astronomical evidence and ...

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

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

Researchers say they found a curious dot on infrared images taken 23 years apart that seems to be moving in a manner consistent with a large, distant planet.