That same cloud gave rise to our entire solar system, including our star, the sun. Keep reading to learn more about Earth's different layers, its atmosphere, and what makes the "blue planet" unique.

There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

Though Pluto has formally been considered a dwarf planet for almost two decades, it still has many lessons left for planetary scientists — including hints about how the solar system formed.

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 ...

The planets in our solar system are a veritable rainbow of colors. But what makes them take on all their various hues, and why does each one look so different?

Discover the order of planets in the solar system. From Mercury to Neptune, explore our solar system and learn more about our cosmic home.

Astronomers have discovered a rare in-sync solar system with six planets moving like a grand cosmic orchestra, untouched by outside forces since their birth billions of years ago.

The photo above is of a planet in a different solar system as seen through a telescope. It’s really, really hard to see planets like this one directly. You need a big, advanced telescope.

The planet currently known as HD 189733b is one of the closest planets astronomers have discovered outside of our own solar system - only 63 light years away. It was first discovered in 2005, when ...