Over the past 250 years, the number of "planets" in our solar system has ranged from six to nine — and, briefly, even 11 — depending on what astronomers knew at the time and how they defined a planet.

Photographs of planets can fool you. A close crop of swirling cloud bands or a patch of rusty dust can look like almost ...

The solar system is composed of the sun, eight major planets, five dwarf planets, over a hundred moons, and countless comets and asteroids. In this article, we will be looking at 21 mind-blowing facts ...