Don't worry though—it's not like one planet simply fell out of the solar system. We'll explain what happened and also show you some tricks for remembering the order of all of the planets that ...

Rocky bodies called protoplanets were thought to have formed slightly earlier in the inner solar system than those beyond the ...

Discover interesting facts about the sun, the solar system's central star that supports all life on Earth.

This process, called accretion, is how everything in the solar system – planets, moons, comets and asteroids – came into being. Telescopes can see young solar systems being born.

All eight of the solar system’s “major” planets appear in this illustration, but the actual number of planetary bodies orbiting our star is far greater. Digital Vision/Getty Images.

This process, called accretion, is how everything in the solar system – planets, moons, comets and asteroids – came into being. Advertisement Article continues below this ad ...

This process, called accretion, is how everything in the solar system – planets, moons, comets and asteroids – came into being. Advertisement Article continues below this ad ...