In the cold, distant reaches of the Solar System, far beyond Pluto, astronomers have just identified what could be a new dwarf planet. It's called 2017 OF 201, a rock that appears to be some 700 ...

Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system ...

Ammonite was discovered using the Subaru Telescope in Hawaii, with follow-up confirmation from the Canada-France-Hawaii Telescope. Its orbit and size officially qualify it as a distant dwarf planet.

WASHINGTON >> Scientists have identified an object about 435 miles wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course. When ...