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.

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

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

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

Pluto was discovered in 1930 in Arizona, but in 2006 scientists decided to cut Pluto from the planetary line up. Here is why ...

Scientists believe that they have discovered a new planet in the Earth's solar system, with NASA naming the finding 'Planet X' ...

Discovered in 1930, Pluto was the ninth planet for over 75 years, orbiting at the chilly fringes of our solar neighborhood. But then scientists at the International Astronomical Union decided ...