Lunar and Planetary Institute






Polaris

Activty: Comet Encounters


Explore!
Children explore the parts of a comet, how comets move in our solar system, and how they leave behind trails of dust that create the meteor showers we see on Earth.

The Activity
Have the children share what they learned about comets in the story. The “About Meteors” section contains more information. Note their responses — correct or incorrect — and review them at the close of the activity.

  • What are comets made of?
  • How are comets and meteor showers related?
  • Ask them to describe the parts of comets?
  • Do comets orbit our Sun?

Invite the children, in groups of 3 to 4, to create their own model of a comet using the materials provided. They should design their comet so that it can be easily carried, and so they can sprinkle comet dust (glitter) at the appropriate places.  Let the children devise ways to meet these criteria. Every comet will be different!

Have the children name their comets. A comet is named using the last name of the person — or people — who first spotted it (like Shoemaker-Levy or Hale-Bopp). If they are working in groups, the name of their comet may be pretty long!

Once they have made their comets, have the children describe its components.

  • What parts do they have in their model?
  • What does the glitter represent?

Take the children outside to a large, safe, paved area, and divide into groups. Help each group use the sidewalk chalk to draw a big model of the solar system — it does not have to be to scale, but the planets should be in the proper order. It is best to have a drawing with a diameter that stretches about 15 feet (5 meters) from the center of the Sun to Pluto.

Draw the different planets, with a rough circle to mark their orbits around the Sun. This would be a good time to discuss “elliptical orbits” by pointing out the highly elliptical orbit of Pluto. This model can be used as a springboard for later discussion of cometary orbits. Walk through the solar system with the children and prompt them to share what they know about comets.

  • Where is our Sun located? Earth? Mars? Pluto?
  • Where do comets come from? (Comets come from beyond Pluto.)

Have the children take their comets to the Kuiper belt beyond Pluto. Invite them to walk their comet in an orbit around the Sun; some comets periodically orbit the Sun. The orbits often are very elliptical, unlike the more circular patterns of the planets. 

  • What happens to the comet — a chunk of dirty ice — as it gets close to our Sun? (As a comet gets closer to the Sun, its surface vaporizes and sheds some of its gas and dust.)
  • What happens to the comet tail as a comet orbits our Sun? (The Sun is always sending out particles from its surface. This creates the solar wind — a constant flow of charged particles from our Sun. The solar wind blows out from the Sun. As the comet moves around the Sun, the solar wind blows the tail outward; the tail is always pointing away from the Sun, regardless of the direction the comet is moving in its orbit.)

As the children carry their comets close to the Sun, have them shake their comets so that cometary dust (glitter) is sprinkled along their path. The closer they get to the Sun, the more “dust” their comet should release.

  • What does the glitter represent in space?(Each piece of glitter is a meteoroid.)
  • Is most of the glitter along the orbits of the planets or in space? (Most is in space.)

Have the children demonstrate the changing direction of the comet tails as their comet moves around the Sun.

The pavement drawing of the solar system should have lots of different colored glitter paths where the comets have orbited the Sun. Have the children trace Earth’s path around the Sun.

  • Does Earth ever encounter the glitter trails of the comets? (Yes)
  • What happens when Earth passes through the trail of dust left behind by a comet? (Meteor showers! Meteor showers occur when Earth passes through the dust trail; the particles in the trail burn up in our atmosphere, creating brilliant streaks of light.)

Activity modified from a comet exercise of the Astromaterials Research Exploration Science (ARES) Educational Outreach Team of the Johnson Space Center.


More Activities

 

Last updated
January 9, 2007

 

Who?
Ages 9–14

How Long?
30 minutes or longer

What's Needed?
For Each Child:

  • • Colored paper, tissue paper, pipe cleaners, Styrofoam balls, craft sticks or dowel rods, and other craft items
  • Glitter (the children within each group should have different colors of glitter)
    Scissors, glue, tape

Connections to the National Science Education Standard(s)

Standard  D (grades K–4): Develop an understanding of the locations and movements of objects in the night sky.

Standard D (grades 5–8): The Earth is located in a system that includes planets, moons, and smaller objects, such as comets, most of which are in regular and predictable motion.