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Asteroids, Part I

Use your best judgment to match the
following words with their definitions.

  1. planet: _____
  2. meteor: _____
  3. asteroid: _____
  4. meteorite: _____
  5. moon: _____
  6. comet: _____
  7. meteoroid: _____
  1. Rocky objects orbiting the sun that are too small to be planets. Their size can range from 10 meters in diameter to 933 kilometers in diameter. Many are not spherical. Most are found in the Asteroid Belt, located between Mars and Jupiter.
  2. Chunks of frozen gases, ice, dust, and rocky debris usually with a nucleus between 1-10 kilometers in diameter surrounded by a gas cloud. They revolve around the sun in highly elliptical orbits. A comet's tail is made of gas and dust that has been driven off its surface by the sun's energy.
  3. A sand- to boulder-sized fragment of solid matter that drifts through the solar system rather than traveling in a regular orbit around the sun.
  4. When a meteoroid enters Earth's (or any celestial body's) atmosphere, it heats up and partially or completely vaporizes. The vapor trail of the disintegrating meteoroid glows. This trail of glowing vapor is called a meteor, also commonly known as a shooting star.
  5. The solid portion of a meteor that survives the journey through the atmosphere and reaches the surface.
  6. A natural satellite orbiting a planet. Moons are smaller than the planets they orbit. Our moon is thought to have formed from the rocky debris ejected when an object the size of Mars collided with Earth. Gravity eventually aggregated the debris into our moon. Some moons are thought to be asteroids captured by planets.
  7. The International Astronomical Union recently set out three criteria for a celestial body to be called a planet: (1) it must orbit the sun; (2) it must have pulled itself into a spherical shape by its own gravity; and (3) it must have cleared other things out of the way in its orbital neighborhood. By this definition, Pluto, Xena, and Ceres are not planets. Pluto and Xena orbit among the icy bodies in the Kuiper Belt. Ceres orbits among asteroids in the asteroid belt.)

Concept Map

On the back of this page create a concept map that links all of these concepts together. Place each term in a box or circle and draw arrows between related terms. Label each arrow with the verb that links the two terms.

Asteroids, Part II
Asteroids, Part III
Asteroid Facts Worksheet
Asteroids: What should be done about Apophis?
Last updated: May 07, 2009        Home