About this Daily Classroom Special: 
Science to Go provides easy yet meaningful science activities for grades k-8. Science to Go was written by Barbara Smith, Magnet Coordinator at Harvard Elementary, Houston (TX) and former Teachers Network web mentor.

Classroom Comets

Close Encounter

To grab attention at the beginning of your lesson about comets, have your own comet sighting! I string up a line of "invisible" fishing line or transparent thread, from one side of the room to another, dropping about 15 degrees from start to finish. (Make sure the line is above head level, so no one will walk into it.) Attach a tail of narrow tissue strips to a heavy foam ball or tennis ball with a thumbtack, to simulate the tail. Hang it from the line with a loop of thread attached to the ball with another thumbtack. Conceal the "comet" behind a ceiling light fixture, air conditioning equipment, or in a small box you have attached to the ceiling. At the appropriate moment, use a meter stick to start the ball sliding down the line. You've got a cheap, fast focus that brings a little excitement to your astronomy lesson!

Toilet Paper Comet

Have a student stand in the middle of the room, playing the part of the sun. Another student, holding a roll of toilet paper, becomes the comet. Determine the path the comet will take around the sun, and as it approaches the sun, pull out paper with one hand to show the growth of the tail. After the comet passes perihelion, tear off small pieces of the tail, until it is far away from the sun and has no tail at all.

Sublimation Simulation

The frozen material in a comet is melted quite easily by the radiation pressure and solar wind. Blow on a pile of chalk dust or a small piece of dry ice (use proper handling safety!), to show how the material is blown away from the sun, forming the tail.

Comet Beliefs

Research what different civilizations thought about comets. Have students portray the attitudes, emotions, and beliefs about comets in a brief presentation.

LINKS

Comet page for upper-level students

Sky & Telescope http://www.skypub.com/sights/comets/comets.shtml

http://www.theworks.com/users/bdrennon/comet.htm