There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

This gas cloud located 500 light years away from our solar system is about to become a planet.This process usually takes a ...

This is the strongest evidence yet of a rocky planet beyond our solar system with an atmosphere. Astronomers using the James ...

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 ...

An "extra exceptional" Tatooine-like exoplanet, orbiting two suns, has been discovered. Astronomers say the "huge" new world ...

Discover which planet is the fastest in the solar system. Learn why Mercury moves at 47 km/s, has the shortest year, and ...

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 ...

Astronomers are increasingly finding planets that do not simply circle their stars in neat, clockwork ellipses but instead trace out paths that look more like intricate choreography. The latest ...

Working through years’ worth of data from an old observational campaign, a team of astronomers have directly imaged a new ...

Researchers using NASA's James Webb Space Telescope have detected the strongest evidence yet for an atmosphere on a rocky ...