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

A recently discovered celestial body is rewriting our knowledge of the Kuiper Belt and maybe challenging the existence of the ...

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

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

As it orbits the sun once every 25,000 years, the celestial body 2017 OF201 travels beyond the Kuiper Belt into a region ...

Learn about the recently discovered trans-Neptunian object that may eventually join Pluto as a dwarf planet, found at the ...

The first observations of Pluto by NASA's James Webb Space Telescope (JWST) reveal dramatic phenomena on its surface, like ...

In the cold, distant reaches of the Solar System, far beyond Pluto, astronomers have just identified what could be a new ...

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