While the James Webb Space Telescope looks for the most distant galaxies ever seen, astronomers have discovered something new ...

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system's outer reaches.

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

The small world was found during a search for the hypothetical Planet Nine, and astronomers say the next time it will reach ...

A new dwarf planet discovery in the outer solar system is challenging the long-standing theory of a hidden giant planet ...

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

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

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

Astronomers have announced the discovery of a new dwarf planet in our solar system, named 2017 OF201. Located far beyond ...

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

Astronomers have discovered a mysterious dwarf planet, 2017 OF201, far beyond Pluto. This discovery challenges existing ...

A new member of the solar system has been detected, the second-largest of its kind, suggesting there may be more like it ...