What you'll learn:
What comets are made of, how they look, and how they feel.
While they are cosmic, comets are made of common ingredients we can easily find here on Earth.
Comets are so exciting to learn about. We often bundle ourselves up, sit by the campfire and patiently wait many times a year for various meteor showers. These showers happen when Earth passes through the debris field of a comet's orbit.
In a previous mini-maker activity we made tennis ball comets as we learned about their tails (yes, plural), and some terminology astronomers use when talking about comets - but what do comets look like? What do comets feel like? What are comets made of?
In this mini-maker activity, you will get to find out! We will make our own comet, one that is so cold that the heat from a hair dryer can even make a tail to look at!
You will need one very special item for this project - dry ice. I found our dry ice at a local grocery store, but I have seen it sold at Walmart and Cash n Carry. Ask the butcher if your store has any, or if they know where you can get some. Typically it costs about $1 a pound. This project uses 5-10 pounds, but you can make dry ice-ice cream with leftovers!
LEARNING ABOUT COMETS
(Aka cool facts about comets to look at while you are engaged in the STEM activity)
What makes meteor showers? Outgassing from comets leaves a trail of debris in its wake. As Earth orbits through that debris field we get meteor showers. This is why meteor showers are annual occurrences always originating from the same spot in space, well-known meteor showers or the Orionids and the Perseids that happen in October.
How are Halley's comet and Mark Twain linked? Mark Twain's life and death were marked by Halley's Comet.
Can comets have craters? It might be well known that comets create craters, but some comets are so large they can have craters themselves. It is difficult to find such comets, however, since the surface changes so rapidly that impact evidence sublimates away!
What are comets made of? Imagine a dirty snowball, a very compacted dirty snowball that might even be the size of a bus - comets are made of ice and dirt. Of course, it isn't just ice like we know ice that make up comets. There are multiple kinds of ice in comets, water ice (like what we put in drinks), ice from carbon dioxide (what we call dry ice), ice from ammonia, and even ice made out of methane (which might be super smelly). All of these types of ice are mixed in with rocks and dust to make a dirty snowball.