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 ...

Mercury is the innermost and smallest of the eight major planets in our Solar System, orbiting closest to the Sun. Though ...

Space has a knack for bending our sense of scale. The Moon feels close enough to touch—after all, we see its craters with ...

LYNCHBURG, Va. (WSET) — If you're trying to get a beautiful look at the planets in our solar system, you're in luck. Between February 25 and February 28, all seven planets in our solar system will be ...

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 ...

Fantasizing about interplanetary exploration is a fun mental exercise, but the harsh realities of life (or lack thereof) in our Solar System is for good reason.

Lucas Brefka receives funding from a NASA Exoplanet Research Program grant. Christopher Palma does not work for, consult, own shares in or receive funding from any company or organization that would ...

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 ...

Roughly four and a half billion years ago the planet Theia slammed into Earth, destroying Theia, melting large fractions of Earth’s mantle and ejecting a huge debris disk that later formed the moon.

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to form in ...

This article was originally featured on The Conversation. Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of ...