An orbital plane is the flat, disk-shaped space that connects the center of the object being orbited with the center of the orbiting objects. Because all planets in our solar system share a similar orbital plane, planets don't run in to each other.

Illustration by Tim Gunther, National Geographic

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  • All the planets, asteroids, meteoroids, and comets in the solar system orbit the sun. This is called heliocentric orbit.

    Almost all these bodies also travel in the same orbital plane, a thin disk surrounding the sun and extending to the edge of the solar system. The orbital plane usually prevents planets or other celestial bodies from bumping into each other.

    Some comets orbit outside the orbital plane, perpendicular or at an angle to the rest of the solar system bodies.

  • Term Part of Speech Definition Encyclopedic Entry
    asteroid Noun

    irregularly shaped planetary body, ranging from 6 meters (20 feet) to 933 kilometers (580 miles) in diameter, orbiting the sun between Mars and Jupiter.

    celestial body Noun

    natural object in space, such as a planet or star. Also called an astronomical object.

    comet Noun

    celestial object made up of ice, gas, and dust that orbits the sun and leaves a tail of debris.

    heliocentric orbit Noun

    regular path around the sun.

    meteoroid Noun

    small, rocky body traveling around the sun.

    Encyclopedic Entry: meteoroid
    orbit Verb

    to move in a circular pattern around a more massive object.

    Encyclopedic Entry: orbit
    orbital plane Noun

    flat space in which a body orbits.

    perpendicular Noun

    at a right angle to something.

    planet Noun

    large, spherical celestial body that regularly rotates around a star.

    Encyclopedic Entry: planet
    solar system Noun

    the sun and the planets, asteroids, comets, and other bodies that orbit around it.

    sun Noun

    star at the center of our solar system.