WASHINGTON (Reuters) - They are the most common type of planet observed in our Milky Way galaxy - two to three times the diameter of Earth but smaller than Neptune, and orbiting closer to their stars ...

Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously ...

An artist's concept depicting the pulsar planet system. (Photo by: Universal History Archive/Universal Images Group via Getty Images) Rarely even acknowledged as the first planets discovered beyond ...

Mercury has long baffled astronomers because it defies much of what we know about planet formation. A new space mission ...

LONDON — 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 ...

All the Latest Game Footage and Images from Twisty Planets Space Puzzle Welcome to Twisty Planets - a 3D Space & Stars Puzzle Game unlike any other. Help little fella Qub escape from the twisty star ...

Astrophysicists at the University of Warwick have found an unusual ring of metal-rich gas orbiting very close around a white dwarf star. The presence of the ring helps solve a problem for astronomers ...

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 ...

Jupiter is already the biggest planet by far in our solar system, but new research suggests it was somehow once even larger than it is now. Twice as large, in fact. To put that into context, those ...

We refer to our own solar system as the solar system, and in a sense, it is the only one of its kind. For centuries, our sun was known as Sol, latin for sun and the Roman equivalent of the Greek sun ...