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

The possibility that an additional planet may be hidden far into the solar system was touted more than a century ago. In 1983 ...

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

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

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

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

An exoplanet discovered in 2020 contains the coldest temperatures ever measured on a planetary body, according to scientists.

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

For over a century, astronomers have wondered if there's an extra planet in our Solar System that we haven't been able to see ...

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