At the center is the sun, a yellow dwarf star that contains 99.8% of the solar system's mass. Everything else — from the eight major planets to dwarf planets, comets, asteroids, and icy objects ...

Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, ...

Astronomers have detected a promising sign of a ninth planet lurking at the the farthest reaches of the Solar System.

The Earth is our planet. It is one of eight planets that move around the sun, each in an oval shaped, elliptical orbit close elliptical orbitAn orbit that is the shape of an ellipse. An ellipse is ...