The chance of a planet forming in the outer reaches of the solar system - a hypothetical Planet Nine - could be as high as 40 ...

Astronomers find evidence of a possible ninth planet beyond Neptune, reigniting the debate about the formation of the Solar ...

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

China's ambitious Tianwen-2 mission will soon be heading to two extremely different space rocks, and should provide vital ...

A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in ...

Today, it’s believed that Jupiter and Saturn, the largest planets, were the first to fully form, both within a few million ...

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be ...

At long last, particles of water–ice have been discovered in the frozen Kuiper Belt of another star. The discovery, made by ...

If the object really is Planet Nine, it would be larger than Neptune and exist 700 times further from the sun than Earth.

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system.

Astronomers have found new evidence that a mysterious ninth planet may be hiding at the edge of the solar ... Satellite (IRAS), launched in 1983, and AKARI, a Japanese satellite which made space ...

Astronomers may have found a new candidate for the role of the ninth planet in the solar system.