Illustration of the Solar System.

Solar System Exploration

Join us as we explore our solar system.

10 THINGS about our solar system

This is an updated montage of planetary images taken by spacecraft managed by NASA’s Jet Propulsion Laboratory in Pasadena, CA. Included are from top to bottom images of Mercury, Venus, Earth and Moon, Mars, Jupiter, Saturn, Uranus and Neptune.

Our solar system has eight planets, and five dwarf planets.

Gray-colored asteroid Bennu is shaped like a spinning top.

About 1.4 million asteroids, and about 4,000 comets are in our solar system.

Our solar system has more than 200 planetary moons.

A swirling Milky Way Galaxy, with our Sun seen on the outskirts.

Our solar system is in one of the Milky Way galaxy’s spiral arms called the Orion Spur.

Sun and planets in solar system

Our solar system takes about 230 million years to orbit the galactic center.

Spitzer Milky Way 1600px

The Milky Way is a barred spiral galaxy.

The blue limb of Earth as viewed from the space station.

Our solar system has many worlds with many types of atmospheres.

The four giant planets – and at least one asteroid – have rings.

Man in the moon with American flag

More than 300 robotic spacecraft have left Earth's orbit, and 24 U.S. astronauts have traveled to the Moon.

Earth blue marble photo

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
An illustration of orange and blue planets and other objects in our solar system shown not to scale, but to illustrate some of the details of each world.
An illustration of our solar system showing the planets far closer together than they are in reality in order to represent the all of the bodies with some detail.
NASA/JPL-Caltech

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. Each planet’s width is compared to Earth’s equatorial diameter. There's also a handy list of the order of the planets moving away from our Sun.

Size Up the Planets
Illustration showing the planets stacked in rows.
The eight planets and dwarf planet Pluto.
NASA

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 look at the mean temperature of the Sun, and the planets in our solar system. The mean temperature is the average temperature over the surface of the rocky planets: Mercury, Venus, Earth, and Mars. Dwarf planet Pluto also has a solid surface. But since the gas giants don’t have a surface, the mean is the average temperature at what would be equivalent at sea level on Earth. 

Get the Forecast
A colorful. symbolic thermometer showing planets in our solar system ordered from hottest a the top to coldest at the bottom. The top of the graphic is red, then it fades to orange, yellow, green, then blue. It has illustrations of the planets.
An illustration of temperatures on planets in our solar system.
NASA
Eyes on the Solar System: A real-time visualization of our solar system using planetary science data.
NASA/JPL-Caltech

Skywatching Resources

  • What's Up

    NASA's monthly skywatching video.

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  • NASA's Skywatching Hub

    Tips and guides for skywatching.

    Explore

  • 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.

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  • Night Sky Planner

    Visible planets and night sky guide.

    Learn More

  • Daily Skywatching Guide

    NASA's detailed guide to watching the sky.

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Featured Missions

A spacecraft hovers over a reddish striped moon with planet Jupiter in the background.

Europa Clipper

NASA's Europa Clipper is the first mission that will conduct a detailed science investigation of Jupiter's moon Europa. The spacecraft launched Oct. 14, 2024.

This artist's-concept illustration depicts the spacecraft of NASA's Psyche mission near the mission's target, the metal asteroid Psyche.

Psyche

Psyche is traveling to a metal-rich asteroid with the same name, orbiting the Sun between Mars and Jupiter. The spacecraft will arrive at the asteroid in August 2029.

NASA's NEO Surveyor is seen in this illustration against an infrared observation of a starfield made by the agency's WISE mission.

NEO Surveyor

Near-Earth Object (NEO) Surveyor is a space telescope designed to hunt asteroids and comets that are potential hazards to Earth. Launch is no earlier than 2028.

A gray spacecraft is illustrated over Venus with one of its instruments scanning the planet below.

VERITAS

VERITAS, and another mission called DAVINCI, will be the first NASA spacecraft to explore Venus since the 1990s. VERITAS will launch no earlier than 2031.

Solar System Feature Stories

animation of clouds moving around Saturn's pole in a hexagonal formation

Storms Across the Solar System

Pluto is reddish and has a heart shape lighter patch in the lower right half of this image from the New Horizons spacecraft.

Find Your Pluto Time

two rocky asteroids in black space

What's That Space Rock?

A full globe view of reddish Mars featuring Valles Marineris - which looks like a huge gash on the planet.

10 Things: Grand Canyons

Go Beyond Our Solar System

  • A spiral galaxy with a disk that glows visibly from the center. It has faint dust threaded through it. A spiral arm curves around the left edge of the disk and is noticeably denser with bright blue spots that hold hot and new stars. On the opposite side, the disk stretches out into a short tail where it covers a distant background galaxy. Other distant galaxies and some nearby stars are visible are also visible in this image.

    Hubble Sees a Celestial Cannonball

    The spiral galaxy in this NASA/ESA Hubble Space Telescope image is IC 3225. It looks like it could have been launched from a cannon, speeding through space like a comet with a tail of gas streaming from its disk behind it. IC 3225 is about 100 million light-years away from Earth.

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  • illustration of WASP-121b exoplanet

    Hubble Explores Alien Atmospheres

    For the past 30 years the Hubble Space Telescope has continued its important mission of uncovering the mysteries of the universe. One of those mysteries that Hubble has helped us understand are exoplanets.

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  • A small flash of white light appears in the middle of a completely black image. The flash expands rapidly, glowing purple and consuming the entire image. The white light shrinks, returning to a pinprick at the center of the image. As it collapses, purple streams and waves pulse outward from white light’s center. Alongside the waves flow hundreds of small galaxies — spiral and spherical collections of dots of light. The galaxies race out from the center, starting as miniscule specks and becoming larger blobs and smudges as they draw closer, speckling the screen.

    Discover the Universe

    Learn about the history of the cosmos, what it's made of, and so much more. The origin, evolution, and nature of the universe have fascinated and confounded humankind for centuries. New ideas and major discoveries made during the 20th century transformed cosmology – the term for the way we conceptualize and study the universe – although much remains unknown. Here is the history of the universe according to cosmologists’ current theories.

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