
Dry Ice Comet with Gas Jets
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What happens when you mix crushed dry ice with dirt and corn syrup? You get a model comet that shoots jets of gas.
You add several ingredients to a plastic-lined bowl of dry ice powder:
- water and dirt (representing dust and minerals)
- starch (to hold the model together)
- corn syrup (to darken it like organic compounds)
- vinegar and rubbing alcohol (representing amino acids and methanol)
As the mixture freezes, you shape it into a clump through the bag. Once you remove the comet, gas jets stream off the surface. Aim a hair dryer at it to simulate solar wind. The jets shift direction as the heat pushes gas away. Weigh the comet every five minutes to track mass loss through sublimation (solid turning directly into gas).
Hypothesis
The hypothesis is that a comet model can be created using dry ice, water, dirt, starch, corn syrup, vinegar, and alcohol.
Science Concepts Learned
Sublimation
Sublimation means a solid changes directly into a gas, with no liquid stage in between. When you build a dry ice comet model, you can see sublimation happen as gas jets stream off the surface. Aiming a hair dryer at the comet simulates solar wind, and the jets shift direction as heat pushes gas away from the solid.
Comets
Comets are balls of ice, dust, and rock that grow bright tails near the Sun. A comet model can be created using dry ice, water, dirt, starch, corn syrup, vinegar, and alcohol. Once formed, the model shoots jets of gas, just like a real comet approaching the Sun.
Method & Materials
You will crush the dry ice, mix the ingredients, and form the mixture into a clump. You will then measure the mass of the comet and observe the jets coming off the comet.
You will need 5 pounds of dry ice, an insulated container, thick gloves, goggles, a mallet, a large plastic bowl, a towel or pillowcase, several large plastic garbage bags, a flat tray, 1 liter of water, dirt, starch, corn syrup or soda, vinegar, rubbing alcohol, a hairdryer, and a flashlight.
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See what’s includedResults
The experiment showed that a comet model can be created using dry ice, water, dirt, starch, corn syrup, vinegar, and alcohol. The model was able to shoot jets of gas and dust, and the mass of the comet was able to be measured.
Why do this project?
This science project is interesting and unique because it allows students to create a model of a comet and observe the jets coming off the comet.
Also Consider
Experiment variations to consider include using different ingredients to create the comet model, such as adding food coloring to the mixture, or using different amounts of dry ice.
Full project details
Additional information and source material for this project are available below.Related video
These videos explain the science behind this project and demonstrate key concepts used in the experiment.
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