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 ...

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 ...

Astronomers have uncovered a massive new trans-Neptunian object, 2017 OF201, lurking at the edge of our solar system. With an orbit stretching 25,000 years and a size that may qualify it as a dwarf ...

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 ...

This story is part of Short Wave's series Space Camp about all the weird, wonderful things happening in the universe. Check out the rest of the series. If you were born in the last century you might ...

The newborn planetary system appears to be emerging 1,300 light-years away around a baby star known as HOPS-315. Planet-forming materials were first identified using NASA's James Webb Space Telescope.

Neptune’s supersonic winds and icy storms revealed a planet so extreme that it forever changed our picture of the solar ...