Astronomers believe they have uncovered evidence of a previously unknown ninth planet lurking in the not-too-distant reaches of the solar system. This hypothetical world, dubbed "Planet Y," could be ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. A composite image comparing the relative sizes of our solar system's known dwarf planets, ...

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 ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. Astronomers have found a distant celestial body — ...

Astronomers have announced the discovery of a new dwarf planet in our solar system, named 2017 OF201. Located far beyond Neptune, it orbits the sun every 25,000 years. When you purchase through links ...

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 ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth than the hypothetical Planet X, which astronomers have been hunting for ...