Planets in Our Solar System

Solar system, assemblage consisting of the Sun—an average star in the Milky Way Galaxy—and those bodies orbiting around it: 8 (formerly 9) planets with about 170 known planetary satellites (moons); countless asteroids, some with their own satellites; comets and other icy bodies; and vast reaches of highly tenuous gas and dust known as the interplanetary medium.

Mercury

Is the smallest planet in our solar system and closest to the Sun—is only slightly larger than Earth's Moon. Mercury is the fastest planet, zipping around the Sun every 88 Earth days.

Venus

Spins slowly in the opposite direction from most planets. A thick atmosphere traps heat in a runaway greenhouse effect, making it the hottest planet in our solar system.

Earth

Our home planet—is the only place we know of so far that’s inhabited by living things. It's also the only planet in our solar system with liquid water on the surface.

Mars

Is a dusty, cold, desert world with a very thin atmosphere. There is strong evidence Mars was—billions of years ago—wetter and warmer, with a thicker atmosphere.

Jupiter

Is more than twice as massive than the other planets of our solar system combined. The giant planet's Great Red spot is a centuries-old storm bigger than Earth.

Saturn

Adorned with a dazzling, complex system of icy rings, Saturn is unique in our solar system. The other giant planets have rings, but none are as spectacular as Saturn's.

Uranus

Seventh planet from the Sun—rotates at a nearly 90-degree angle from the plane of its orbit. This unique tilt makes Uranus appear to spin on its side.

Neptune

The eighth and most distant major planet orbiting our Sun—is dark, cold and whipped by supersonic winds. It was the first planet located through mathematical calculations.