Definition: A celestial object consisting of a nucleus of ice and dust and, when near the sun, a “tail” of gas and dust particles pointing away.
History: The first comet was spotted by Gottfried Kirch in November 1680 with a telescope. However, the Chinese recorded seeing Halley’s comet in 240 B.C. Halley becomes a famous comet who makes a pass by earth every 75 years!
Related Learning Ideas: While learning about comets, study the elements that make up a comet. Learn abut the Halley’s comet orbit. Complete a unit study on Maria’s Comet. Read about the theory of the dinosaurs and the comet.
Learning About Comets Websites
NASA – How to Make Comet Soup: Scientists are putting together a recipe for comet soup – “the primordial stuff of planets, comets and other bodies in our solar system.”
The Comet’s Tale by Segway (Science Education Gateway): This is the site we used for learning about comets. Meets standards for Grades 5-8.
Deep Impact: Learn the comet song. For grades K-5
Two Ways to Make a Comet: This has great pictures & steps especially for the younger learners.
Reading about Comets
Click picture for link to Amazon
Today’s experiment is from the instructional pages on the site “The Comet’s Tale” at http://cse.ssl.berkeley.edu/SegwayEd/lessons/CometsTale/com.html. Although this is set-up for a classroom demonstration it can easily be adapted for homeschoolers.
Step 1 – Arrange the Materials
Materials Used: Mixing Bowl, garbage liner, water, sand or dirt, organic material (we used dark corn syrup), mixing utensil, googles, hammer, ammonia, DRY ICE…and don’t forget the LEATHER gloves. These will be an ABSOLUTE must!
This is the time to instruct the student(s) about safety. Dry ice can cause burns since it is -79° C, use of LEATHER gloves are an absolute must. Since dry ice is carbon dioxide we executed this experiment outside. We also wore safety goggles. Even Momma.
Step 2 – The Experiment
This section covers steps 2-12 on the instruction sheet. We followed the experiment step-by-step. I read the instructions followed by the narrative. Calving and Gabby were today’s scientists. Bella decided to stay back and watch from a safe distant. (She wasn’t thrilled about the idea of dry ice.)
Step 2 is merely preparing the mixing bowl by placing a liner into the bowl.
Gabby placed 2 cups of water to the bowl. I should have double-checked this. We poured in too much water. After this she put in 1/4 cup sand. At this point I began having her mix the two ingredients together. During this time we discussed what water is made of (2 parts Hydrogen, 1 part Oxygen). One fact we learned: There is at least 10 times more hydrogen than any other substance in the universe.
Step 5 was amusing. The directions call for a “dash of organic material (e.g. corn syrup)”. Um, I’ve never heard a dash used with liquid. But ok, we went for it. Not sure if we got the right amount. But now we had a watery, muddy albeit sweet smelling mix. Did you know that scientists have found a simple form of sugar in the Milky Way? Cool, huh?!
Step 6, add 1/8 cup of ammonia. To which Gabby promptly proclaimed, “Now it stinks!” Exactly as instructed; “You should have a muddy, slightly smelly sludge”.
Now let the fun begin…
Calvin was chosen to handle the dry ice. Gabby was not happy but she quickly recovered. One thing we discovered: the gloves were heat-resistant. NOT good for handling dry ice. ESPECIALLY if one finger has a hole in it! Luckily no burn, but he was close. I purchased basic leather work gloves from the store. Those worked much better.
To prepare the ice we placed it into a garbage bag. Calvin took the hammer and beat on it a few times. Here’s another step we should have read the directions better. Breaking up in pieces and *CRUSH* the ice. We didn’t exactly crush, more like splinter.
The dry ice is COOL! Bella jumped up at this point. Seriously…this is coming back at Halloween time! Once the dry ice is added to the ingredients, stir vigorously. About 30 seconds, because the water will freeze right away. We used a wooden spoon that I wasn’t worried about being ruined. It turned out ok. The instructions said to wait for a minute or two. So…we decided to see what happens when we added a bunch of ammonia and dry ice together. I think he was hoping for an explosion. We’ll share about that in another post.
Meanwhile back at the bowl…
It was at this point we discovered that we didn’t *QUITE* do something right. We ended up with a frozen jumble of “rocky” material. So, we had the ingredients for a comet, but not the shape. That’s ok, I think what we ended up with was pretty cool. The kids enjoyed themselves, I enjoyed taking pictures and in the end the mess wasn’t that bad! A win-win for us!