Solar System Exploration
Join us as we explore our solar system.
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 more than 200 planetary 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 Overview
Our solar system has one star, eight planets, five officially named dwarf planets, hundreds of moons, thousands of comets, and more than a million asteroids.
About the Planets
Learn about the planets in our solar system.
The solar system has eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. There are five officially recognized dwarf planets in our solar system: Ceres, Pluto, Haumea, Makemake, and Eris.
Get the Facts
Which Planet is Biggest
Which planet is smallest? What is the order of the planets as we move out from the Sun?
This is a simple guide to the sizes of planets based on the equatorial diameter – or width – at the equator of each planet. There's also a handy list of the order of the planets moving away from our Sun.
Size Up the Planets
What’s the Weather Like Out There?
We mean waaaay out there in our solar system – where the forecast might not be quite what you think.
Let’s check the temperature of the Sun, and the planets in our solar system.
Get the Forecast for the Planets
We're on a Mission to Touch the Sun
Parker Solar Probe
On a mission to “touch the Sun,” NASA's Parker Solar Probe became the first spacecraft to fly through the corona – the Sun’s upper atmosphere – in 2021. With every…
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Skywatching Resources
Hubble's Night Sky Challenge
Do you have a telescope? Each month in 2025, the Hubble team will release a new set of objects for you to explore. Compare your view to Hubble’s, then submit your observations to the Astronomical League to earn recognition for your achievement.
Avalanches, Icy Explosions, and Dunes: NASA Is Tracking New Year on Mars
Instead of a winter wonderland, the Red Planet’s northern hemisphere goes through an active — even explosive — spring thaw.…
Read the Story
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. Launch is no earlier than 2028.
VERITAS
VERITAS and DAVINCI will be the first NASA spacecraft to explore Venus since the 1990s. VERITAS will launch no earlier than 2031.
NASA’s Hubble Celebrates Decade of Tracking Outer Planets
Encountering Neptune in 1989, NASA’s Voyager mission completed humankind’s first close-up exploration of the four giant outer planets of our…
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Go Beyond Our Solar System
Solar System News
Celebrating 20 Years: Night Sky Network
NASA Mars Orbiter Spots Retired InSight Lander to Study Dust Movement
NASA DAVINCI Mission’s Many ‘Firsts’ to Unlock Venus’ Hidden Secrets
NASA Outlines Latest Moon to Mars Plans in 2024 Architecture Update
