Learn about the solar system in our new What If song. Explore planets, moons, and cosmic wonders through music and imagination.

The Sun's formation caused temperature differences in the surrounding disk of gas and dust. Inner, hotter regions formed rocky planets from less volatile elements. Outer, colder regions allowed ...

This artist’s concept depicts one of the solar system’s inner planets slamming into Earth after being nudged on a collision course by a passing star. Such a world-shattering cataclysm is extremely ...

All of our solar system’s planets are lining up to parade through the night sky at once. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known as a ...

When 'Oumuamua traversed our solar system in 2017 it was the first confirmed Interstellar Object (ISO) to do so. Then in 2019, Comet 2l/Borisov did the same thing. These are the only two confirmed ...

Could a lonely planet wander aimlessly through the restless galaxy change the subtle dance of gravity within our solar system? Astronomers have new cause to investigate. With powerful telescopic ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. After decades of ...