We know that comets aren't much more than dirty snowballs of ice and gases soaring through space. Comets are usually composed of organic material, dirt, dust, and frozen gases.
Because the materials are so common, it is easy for us to make our very own comet, right in our own backyard- with a little help from an adult!
To make your own comet, find a parent, teacher or other adult willing to help you, and follow these instructions carefully:
Before you begin to make you comet, you will need a whole list of supplies and safety gear. It is best to find a nice sturdy table to work on, or work on the ground, since you will need to hammer and crush ice to make your comet.
Dry Ice is frozen carbon dioxide (CO2), and is VERY cold. You should not touch it with bare hands! You can buy dry ice in small quantities at an ice cream store. Use gloves when handling dry ice, and keep it in an ice chest. Do not put dry ice in the refrigerator or other air-tight/sealed container! Dry ice is made of gases that can build up, and blow the door off of a refrigerator!
Line the bottom of your mixing bowl with one opened garabage bag. This will help you shape your comet, and make clean up easier later!
Add four cups of water to the mixing bowl. Although not much liquid water is found in space, the atoms that make water- Hydrogen and Oxygen, are highly abundant in the Solar System!
Add a little organic material (corn syrup) and dirt, and stir everything until it is well mixed in the bowl. Organic material is anything that contains the essential elements of Carbon (C), Hydrogen (H), Nitrogen (N) or Oxygen (O).
Add some Ammonia (NH3: another organic) to the mixture. Ammonia is the main component of Jupiter's atmosphere, and is abundant in space!
Put three garbage bags inside one another until you have one bag three layers thick. Put on some well-insulated (warm) safety gloves and place the dry ice in three garbage bags .
Crush the dry ice by pounding it with a hammer. You want the pieces to be small so that they can be packed into a ball later.
Add the dry ice to the other ingredients in the bowl. Stir the mixture of organics, water, and dry ice very well. Stirring this mixture is representative of the rotation of the nebula that "mixes" comets!
Continue stirring until mixture is almost totally frozen. This mixture is very cold, but in space, where comets form, temperatures are much, much colder!
Lift the garbage bag out of the plastic bowl, and with the comet still in the bag, shape your comet just like you would shape a snowball.
Unwrap the comet as soon as it freezes enough to hold its shape.
Your comet may not be perfectly round, but that's OK! Real comets aren't always round either!