Supplies and Materials
Below, you’ll find a handy supply document you can download, with shopping lists for small and large groups and a range of cost estimates, depending on how much of the supplies you can acquire from available supplies or donations by participants.  With a minimal outlay, you and your group can experience being comet chasers–observers of comets.
Basically, you need a bunch of badminton birdies for your comet heads—keep in mind you don’t need performance-grade shuttlecocks or even new ones. If your high school has a badminton team, they will have worn-out birdies you can take off their hands.  A grungy, beat-up birdie makes a more realistic comet head.
Birdies for Comets
And you need a bunch of ribbon—curling ribbon for the comet tails. The supply sheet estimates ribbon packages at around $8, but if you look at this photo, you’ll see the last time I bought supplies, it was out of the clearance bin at $2. And if you can get one in five of your participants to bring in a roll to share, it won’t cost you a dime.
Zoom Out–Yes! Here’s All You Need To Make Comets
The one oddball item is that tulle fabric ribbon for the big comet. This you might have a hard time finding in your junk drawer unless you’ve been helping a bride make wedding tchochkes. But for $10 you can buy enough to make three huge comets. Cut five-yard lengths and tie one end of each to a vane of a single birdie, allowing a few inches of extra length to fan out as the comet’s “coma”. Tulle scrunches up easily, so even a six-inch-wide ribbon will feed through the holes between the birdie’s vanes.
Detail–How To Tie Fabric Tails
You should be able to borrow a portable fan and a playground or soccer ball. If you can’t, it will take a roughly $25 expenditure to get those items in stock—a cost you can recoup in part by either donating it to the group you’re working with or simply deducting the expense as part of your cost of volunteering.
And it is presumed you can find a pencil, which makes holding the small model a little easier when you’re doing the demo with the fan;Â here’s the trick for hooking the pencil to the comet head:
Holder For Fan Experiment
Depending on how good you are at scrounging supplies and locating soccer balls, your costs will range from $10 to $85 for typical group sizes.  The spreadsheet I use has a calculation column to adjust the requirements list for other class sizes So, if you want a copy of this fully-functional workbook, “like” the Facebook page & I’ll send you one via a Facebook “message”. (You can also try emailing me through the “contacts” page here, but you’ll get a faster response on FB.) Your FB contact will be used for nothing other than sending you a file and boosting the “likes”-count on my page. [Insert maniacal laughter, if desired.]
Meanwhile, you can get the static workbook as a pdf right away:
Resources and References
Now that you are all excited about comets, here are some fun places to go where you can find more cometary material:
A lovely one-page summary from the Spaceguard Program (sponsored by the European Space Agency) gives a clear description of comet tail structure and dynamics, including a neat animation of what both tails look like as the comet proceeds around the sun. The ion tail streams straight back, while the dust tail is curved a bit as the particles within the dust tail blend movement due to their individual orbits about the sun and the forces of the radiation pressure. Net, both tails roughly point away from the sun, as in our demonstration.
Sweet page from NASA with helpful animations and clear descriptions.
Follow the European Space Agency’s comet-chasing spacecraft, Rosetta, as it aims for the first robotic landing on a cometary nucleus.
Read this: a “real” science article with a good set of detailed discussions of the types of comet tails and how they work.
Or, try this excellent piece by freelance science writer Craig Freidenrich on the inner workings of comets.
The Swinburne Centre for Astrophysics and Supercomputing’s educational site helps with details on the structure of comets.
Explore a public-domain catalog of Solar System images, from Hubble and other spacefarers.
Discover how Oort clouds may be one way star systems interact directly with one another, because the Oort clouds project so far out.
See the invisible part of a comet.
Find out all about radiation pressure.
Plan to catch sight of the meteor shower sponsored by Comet Halley.
Explore the origins of comets at this UC Berkeley site.
Check out NASA’s solar system photo gallery, with images from NASA and European Space Agency exploration missions and telescopes.
Visit the Lunar and Planetary Institute’s educational site, with even more hands-on activities for young astrophysicists. Roam their site for educator workshops and more.
OK, seriously, I’m not the only science blogger keen on comets.
A new comet is incoming this month (May 2014).
Our guy Euler was the first one to suggest that light exerts pressure, but we had to wait over 100 years to get to Maxwell, who proved it, and then another quarter-century went by before some Russians managed to measure radiation pressure. (Also, gotta love Google Books.)
Oh, and by 1915 the proof of radiation pressure made it into Scientific American.