The object’s aphelion – the farthest point on the orbit from the Sun – is more than 1,600 times that of the Earth’s orbit,” said Sihao Cheng of the Institute for Advanced Study, discussing the ...

A US-based trio hunting this elusive world has stumbled on what appears to be a new dwarf planet in the solar system's outer reaches.

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the ...

Some astronomers say the strange, clustered orbits of icy rocks beyond Neptune indicate that something big is out there, ...

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

Using the James Webb Space Telescope (JWST), astronomers from Johns Hopkins University (JHU) and elsewhere have detected ...

The International Astronomical Union’s Minor Planet Center, which catalogs new moons and other small bodies in the solar ...

James Webb Space Telescope detects frozen water in a distant young star system, revealing a Kuiper Belt–like icy debris disk.

Webb’s powerful instruments have detected crystalline water ice in a distant star system, offering rare insight into planet ...

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

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 ...