/Vocabulary Lists

Outer Space Vocabulary

Outer Space Vocabulary Words

  1. asteroid | see definition»

    one of thousands of rocky objects that move in orbits mostly between those of Mars and Jupiter and have diameters from a fraction of a mile to nearly 500 miles (800 kilometers)

  2. black hole | see definition»

    a heavenly body with such strong gravity that light cannot escape it and that is thought to be caused by the collapse of a massive star

  3. comet | see definition»

    a small bright heavenly body that develops a cloudy tail as it moves in an orbit around the sun

  4. dwarf planet | see definition»

    a heavenly body similar to a planet but too small to clear other objects from its orbit

    Dwarf Planets in our solar system:

    Ceres: a dwarf planet that orbits within the asteroid belt with a mean distance from the sun of 2.7 astronomical units (260 million miles) and a diameter of 590 miles (950 kilometers)

    Eris: a dwarf planet with a mean distance from the sun of 67 astronomical units (6.2 billion miles) and a diameter of 1500 miles (2400 kilometers)

    Haumea: a dwarf planet that orbits within the Kuiper belt with a mean distance from the sun of 43 astronomical units (6.45 billion kilometers) and a diameter of approximately 890 miles (1,430 kilometers)

    Makemake: a dwarf planet that orbits within the Kuiper belt with a mean distance from the sun of 46 astronomical units (6.85 billion kilometers) and a diameter of approximately 930 miles (1,500 kilometers)

    Pluto: a celestial object that orbits the sun at an average distance of 3.7 million miles (5.9 million kilometers) and has a diameter of about 1500 miles (2300 kilometers) and is often considered one of the planets

  5. galaxy | see definition»

    any one of the very large groups of stars that make up the universe

  6. light-year | see definition»

    a unit of length in astronomy equal to the distance that light travels in one year or about 5.88 trillion miles (9.46 trillion kilometers)

  7. meteor | see definition»

    one of the small pieces of matter in the solar system that enter the earth's atmosphere where friction may cause them to glow and form a streak of light

  8. Milky Way | see definition»

    a broad band of light that stretches across the sky and is caused by the light of a very great number of faint stars

  9. moon | see definition»

    a smaller body that revolves around a planet

  10. planet | see definition»

    any large heavenly body that orbits a star (as the sun)

    Planets in our solar system:

    Mercury: the planet that is nearest the sun and has a diameter of about 3000 miles (4700 kilometers)

    Venus: the planet that is second in order of distance from the sun and has a diameter of about 7,500 miles (12,100 kilometers)

    Earth: the planet that is thirds in distance from the sun. The planet that we live on.

    Mars: the planet that is fourth in order of distance from the sun, is known for its redness, and has a diameter of about 4200 miles (6800 kilometers)

    Jupiter: the planet that is fifth in order of distance from the sun and is the largest of the planets with a diameter of about 89,000 miles (140,000 kilometers)

    Saturn: the planet that is sixth in distance from the sun and has a diameter of about 75,000 miles (120,000 kilometers)

    Uranus: the planet that is seventh in order of distance from the sun and has a diameter of about 32,000 miles (51,000 kilometers)

    Neptune: the planet that is eighth in order of distance from the sun and has a diameter of about 31,000 miles (50,000 kilometers)

  11. solar system | see definition»

    the sun and the planets, asteroids, comets, and meteors that revolve around it

  12. star | see definition»

    any of the heavenly bodies except planets which are visible at night and look like fixed points of light

  13. sun | see definition»

    the heavenly body in our solar system whose light makes our day and around which the planets revolve

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