Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory ...

For the dwarf planet candidate, one trip around the sun takes over 24,000 years. Its orbit challenges a proposed path for a hypothetical Planet Nine.

In searching for the elusive Planet Nine, researchers instead turned up a different resident in our cosmic backyard.

The James Webb Space Telescope (JWST) has discovered that a hazy sky over frozen Pluto is helping to cool the dwarf planet's ...

A planet far, far away. A possible dwarf planet, ... that Planet Nine would "nudge the closest part of 2017 OF201's trajectory inward until Neptune flung it out of the solar system." ...

Plus, an in-depth look at how the West Texas city of Seminole reacted when a measles outbreak tore through the region.

How long does it take Pluto to orbit the sun? Learn more about how this planet makes one lap around our Solar System.

A possible new dwarf planet has been discovered at the edge of our solar system, so far-flung that it takes around 25,000 years to complete one orbit around the sun. The object, known as 2017 OF201, ...

A team of researchers has outlined how a new "direct fusion drive" propulsion system could allow us to reach Sedna this ...

TOI-6894 b, the largest exoplanet relative to its host star yet seen, doesn’t fit the most widely accepted formation model ...