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 about the inner planets, the outer planets, and the dwarf planets.
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.
Interstellar Comet Cruises Past Mars, Behind Sun, Toward Jupiter Flyby Next Year
Only the third known object to venture into our solar system from interstellar space, Comet 3I/ATLAS poses no threat to Earth, but is taking a tour past our celestial neighbors. NASA has been studying the icy visitor with space telescopes including Hubble, Webb, and SPHEREx, as well as multiple other assets. The comet is on course to pass behind the Sun in late October, and venture past Jupiter in March 2026, on its way out of our solar system.
Learn More About Comet 3I/ATLASView Interstellar Comet 3I/ATLAS Through NASA’s Multiple Lenses
Since the interstellar comet was discovered July 1, a dozen NASA assets have captured and processed imagery of the icy interloper, and several others will have opportunities to capture more images as the comet continues to pass through our solar system. Its path runs far beyond Earth; at its closest — on or around Friday, Dec. 19 — comet 3I/ATLAS will be about 170 million miles away, or nearly twice the distance from Earth to the Sun. NASA spacecraft will continue to observe the comet as it makes its journey through the solar system, passing the orbit of Jupiter in spring 2026.
Learn More
Eyes on the Solar System
Featured Missions
NEO Surveyor
NEO Surveyor will hunt asteroids and comets that are potential hazards to Earth. Launch is no earlier than September 2027.
Europa Clipper
Europa Clipper launched Oct. 14, 2024, to conduct a detailed investigation of Jupiter's moon Europa.
VERITAS
VERITAS and DAVINCI will be the first NASA spacecraft to explore Venus since the 1990s. VERITAS will launch no earlier than 2031.
Featured Articles
Resources
Explore curated collections of resources, including activities that can be done at home, as well as videos, animations, handouts, and online interactives.
