Mercury is the innermost and smallest of the eight major planets in our Solar System, orbiting closest to the Sun. Though only slightly larger than Earth’s Moon, Mercury endures some of the most ...

PASADENA, Calif.–The International Astronomical Union (IAU) today downgraded the status of Pluto to that of a “dwarf planet,” a designation that will also be applied to the spherical body discovered ...

Our Solar System has eight planets, a few dwarf planets and more than 200 moons. But wait. Are you seeing double? Or did every planet suddenly get a twin? Where would each planet’s double fit in? Why ...

This artist’s concept depicts one of the solar system’s inner planets slamming into Earth after being nudged on a collision course by a passing star. Such a world-shattering cataclysm is extremely ...

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 ...

When I was a kid, there were nine planets. Now we know of thousands! But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might ...

James is a published author with multiple pop-history and science books to his name. He specializes in history, space, strange science, and anything out of the ordinary.View full profile James is a ...

Stargazers are in for a treat this week as a planetary parade is set to take place - just a month after the last planetary spectacle. This latest planetary alignment or "planet parade" - set to take ...

Theorbits of Jupiter, Saturn, Uranus and Neptune may have been altered by the fly-by of an enormous object from deep space, billions of years ago. According to a pre-print research paper, which is yet ...