Solar System Exploration
Join us as we explore our solar system.
Planets
Dwarf Planets
10 THINGS about our solar system
1. Many Worlds
Our solar system has eight planets, and five dwarf planets.
2. Small Worlds, Too
About 1.4 million asteroids, and about 4,000 comets are in our solar system.
3. Lots of Moons
Our solar system has hundreds of moons.
4. Meet Me in the Milky Way
Our solar system is in one of the Milky Way galaxy’s spiral arms called the Orion Spur.
5. A Long Way Around
Our solar system takes about 230 million years to orbit the galactic center.
6. Spiraling Through Space
The Milky Way is a barred spiral galaxy.
7. Diverse Atmospheres
Our solar system has many worlds with many types of atmospheres.
8. Ring Worlds
The four giant planets – and at least one asteroid – have rings.
9. Getting Out There
More than 300 robotic spacecraft have left Earth's orbit, and 24 U.S. astronauts have traveled to the Moon.
10. Life as We Know It
So far, Earth is the only place we've found life in our solar system.
Solar System Facts
Our solar system includes the Sun, eight planets, five officially named dwarf planets, hundreds of moons, and thousands of asteroids and comets.
Our solar system is located in the Milky Way, a barred spiral galaxy with two major arms, and two minor arms. Our Sun is in a small, partial arm of the Milky Way called the Orion Arm, or Orion Spur, between the Sagittarius and Perseus arms. Our solar system orbits the center of the galaxy at about 515,000 mph (828,000 kph). It takes about 230 million years to complete one orbit around the galactic center.
About the Planets
Learn all about the inner planets, outer planets, dwarf planets, and exoplanets.
What makes a planet a planet? Why are some planets, like Earth, rocky while the gas giants don't even have a solid surface? Explore the eight planets and five dwarf planets in our solar system. Discover how they compare in size, atmosphere, and distance from the Sun. Learn about exoplanets—planets that are orbiting other stars or floating free, untethered to any star.
Moons in Our Solar System
Earth's Moon is not alone. Learn about all of the moons in our solar system.
Our solar system has hundreds of moons, and they come in a variety of shapes and sizes. Many moons orbit planets, and even some asteroids have moons.
What’s Up: November 2026
Catch Taurid and Leonid meteors, spot Mars near Jupiter, celebrate Voyager 1's light-day milestone, and watch November's supermoon.
Watch Now
Eyes on the Solar System
Featured Missions
Europa Clipper
Europa Clipper launched Oct. 14, 2024, to conduct a detailed investigation of Jupiter's moon Europa.
NEO Surveyor
NEO Surveyor will hunt asteroids and comets that are potential hazards to Earth.
Featured Stories
Resources
Explore our collections of resources, including activities that can be done at home, as well as videos, animations, handouts, and online interactives.
