Our Solar System

Our Galactic Neighborhood
MORE

ON THIS PAGE

    The planetary system we call home is located in an outer spiral arm of the vast Milky Way galaxy. It consists of the Sun (our star) and everything that orbits around it. This includes the eight planets and their natural satellites (such as our moon), dwarf planets and their satellites, as well as asteroids, comets and countless particles of smaller debris.

    Most stars host their own planets, so there are likely tens of billions of other solar systems in the Milky Way galaxy alone. We've discovered thousands of planetary systems around other stars.

    Go farther. Explore Our Solar System in Depth ›

    10 Things to Know About Our Solar System

    10 Need-to-Know Things About the Solar System

    1

    One of Billions

    Our solar system is made up of a star, eight planets and countless smaller bodies such as dwarf planets, asteroids and comets.

    2

    Meet Me in the Orion Arm

    Our solar system orbits the center of the Milky Way Galaxy at about 515,000 mph (828,000 kph). We’re in one of the galaxy’s four spiral arms.

    3

    A Long Way Round

    It takes our solar system about 230 million years to complete one orbit around the galactic center.

    4

    Spiraling Through Space

    There are three general kinds of galaxies: elliptical, spiral and irregular. The Milky Way is a spiral galaxy.

    5

    Good Atmosphere(s)

    Our solar system is a region of space. It has no atmosphere. But it contains many worlds—including Earth—with many kinds of atmospheres.

    6

    Many Moons

    The planets of our solar system—and even some asteroids—hold more than 150 moons in their orbits.

    7

    Ring Worlds

    The four giant planets—and at least one asteroid—have rings. None are as spectacular as Saturn’s gorgeous rings.

    8

    Leaving the Cradle

    More than 300 robotic spacecraft have explored destinations beyond Earth orbit, including 24 astronauts who orbited the moon.

    9

    Life as We Know It

    Our solar system is the only one known to support life. So far, we only know of life on Earth, but we’re looking for more everywhere we can.

    10

    Far-Ranging Robots

    NASA’s Voyager 1 is the only spacecraft so far to leave our solar system. Four other spacecraft will eventually hit interstellar space.

    FAQ

    FAQ

    What Spacecraft are Headed into Interstellar Space?

    Five spacecraft have achieved enough velocity to eventually travel beyond the boundaries of our solar system. Two of them reached the unexplored space between the stars after several decades in space.

    • Voyager 1 went interstellar in 2012 and Voyager 2 joined it in 2018. Both spacecraft are still in communication with Earth. Both spacecraft launched in 1977.
    • NASA's New Horizons spacecraft—currently exploring the an icy region beyond Neptune called the Kuiper Belt—eventually will leave our solar system.
    • Pioneer 10 and Pioneer 11 also will ultimately travel silently among the stars. The spacecraft used up their power supplies decades ago.

    Our Solar System News