So you want to know everything there is to know about the solar system? The first and most important question you might want to get out of the way is: what, exactly, isthe solar system? As Mental Floss editor-in-chief Erin McCarthy tells us, "It's a group of celestial bodies located within the Milky Way galaxy."

At the center of these bodies is the Sun, which is orbited by eight planets; more than 150 moons; and millions of meteoroids, comets, asteroids, and a handful of dwarf planets (sorry, Pluto). But it's the Sun—a.k.a. that shining, 4.5 billion-year-old star in the middle of it all—that accounts for 99 percent of the solar system's total mass. (Think about that the next time you're shading your eyes from its glare.)

In this all-new edition of The List Show, Erin is sharing nearly two dozen fascinating facts about our solar system, including the reasoning behind Pluto's demotion (blame it on Eris, the first known dwarf planet). For more out-of-this-world facts, you can watch the full episode below.

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