As mentioned in the notes for project leaders, it’s best to repeat the procedure at least twice–three times if the class is large, to ensure that everyone has a chance to participate in the “safe” portions of the activity and to produce a variety of comets to observe.
Purchase dry ice in advance by as much as a day (purchase at the higher end of the quantity range if you need to store it overnight) and store wrapped in insulating material, but not tightly sealed. (Frozen CO2 will sublime to gas and can even explode a container that is sealed too tightly.) A small non-airtight cooler tucked into another lightly-closed, non-airtight cooler works fine, especially if wrapped in a blanket and stored in a cool location.
For the ice-cream topping, choose a small bottle with a squirt-style top full of caramel- or chocolate-flavor syrup for ice-cream sundaes. Do NOT purchase hard-shell toppings; stick to sticky sugar syrups. Be prepared to fend off requests to sample the syrup.
For ammonia, do not use pure ammonia; simply choose a basic non-sudsy ammonia-based cleanser. A âsport-topâ (squirting-style) water bottle about half-full of ammonia works well and keeps the ammonia away from hands, eyes, and clothing. However, be sure to clearly label the bottle with the contents.
For trash bags, choose a good, sturdy brand. They’ll take significant abuse!
Please note carefully that most equipment is required to be either plastic or wood.
Â
Per comet
For about 3-4 comets, allowing for waste and failures
Â
Estimated cost
(2015 prices)
Good sturdy âtall kitchenâ garbage bag, cut down one long edge to make a liner for the bowl
1
2
(have a second on hand in case the original tears)
$0.50
($12 for box of 45)
Additional âtall kitchenâ garbage bags
3
Open the bags and layer them one inside the other, to create a triple-thick bag
6
Have a second layered set of 3 bags on hand in case of tears
$1.50
($12 for box of 45)
Large plastic mixing bowl, 2-cup plastic measuring cup, tablespoon measure, large wooden spoon
1 of each
Reminder:Â for safety, use plastic containers and a wooden spoon
1 of each
Bring from home or borrow from volunteers
Water
2 cups
2 quarts on hand
(store in a pitcher for measuring out in 2-cup quantities)
n/a
Sand or fine gravel
2 tablespoons
½ cup
zero
Ammonia
One squirt (about 1 tablespoon)
½ cup
$1.50
($10 for 28-ounce bottle)
Ice-cream topping
One squirt (about 1 tablespoon)
About ½ cup (Bring at least a 4-ounce container of syrup.)
$6.50
Dry ice
2 cups of dry ice, after crushing.
About 7-10 pounds of dry ice.
$15($1.50 per pound)
Safety goggles
1 pair, adult size
1-2 pair, adult or child size (depending on student age)
1 pair, adult size
1-2 pair, adult or child size (depending on student age)
If not available in classroomâone-time purchase for reuse in many projects. $5 each
Heavy work gloves
1 pair, to fit Project Leader
1 pair, to fit Project Leader
Use own gloves or borrow from volunteer (a new pair would cost about $10-12)
This category of the blog is dedicated to science & technology topics that I think may interest my fellow nerds.
(Note: Original post: 2012. A few updates were made during site reorganization in January, 2021.)
For starters, I’ll be posting in the blog regularly under Astronomy & Astrophysics. (In some of these older posts the category is tagged Pixel Gravity.) To jump straight to those posts, visit the PG Archive–readily accessible in the menu. For some time now, I’ve been running the social-media support for the program that made the picture you see here. I’ve been posting about robots, space exploration, astronomy, big steps in physics, and so on. Sometimes, the space available for a posting on Facebook is too restrictive. So those kinds of discussions will move here.
What qualifies me to write about this stuff? Well, I’ve admitted elsewhere that we are a family of hypernerds. That’s not my term. It was invented and applied by one of our charming (adult) offspring. It’s not a misnomer As a family, we are 40% engineers and 60% scientists.
I’m a power systems engineer, which in my case means I’ve made a career out of simulating how power plants and electric and gas networks operate.
My husband is a computational physicist, specializing in solar physics. Want to know what’s going on inside the sun? He’s your guy.
Our youngest son is too busy for now, building catapults and robots on his way to a mechanical-engineering degree at UC Santa Barbara. (Update: graduated, with honors. Currently open to job offers.)
After two summer internships in NASA’s astrobiology group, our middle son is working on an honors thesis project on metabolic processes of microbes in deep serpentine wells, attracted by the prospect of doing biology fieldwork in extreme ecosystems right here on planet Earth. (Update: he’s now nearly done with his Ph.D.)
And the oldest escaped from UC Berkeley’s astrophysics program with a degree and a desire to never return to academia. He built Pixel Gravity instead.
What’s “Pixel Gravity“? It’s a detailed, graphical astrophysics simulator with real-time controls. It looks sort of like a game, and it’s fun to play with, but it’s also a serious science tool As an ânâbodyâ simulator, it lets users model complex groups of many objects, from the solar system to galaxies. Most of the other easy-to-use programs available online limit the number of objects or lack physical accuracy, so (for example) relativistic effects on motion near a black hole are not handled properly, if at all. University researchers have access to extremely-detailed models, but those require supercomputers. Pixel Gravity provides accurate modeling on personal computers and is priced low so that even students can explore gravity in action. In addition to Newtonian gravity, Pixel Gravity models the additional effects of atmospheric drag, general relativity, and dark-matter, as well as user-defined forces. Plus, the software package includes helpful tools for curriculum development such as a tutorial-builder and video-production capability. (Update: Pixel Gravity is at present a retired product–contact us if you’d like a copy to play with.)
So, in short, the topics under this heading are just the kind of things we talk about at our house. So if you come to dinner, you don’t need to bring a foodie specialty. But you might scan the latest issue of Scientific American.
New Horizons has flown past Pluto successfully, and is now on the way to check out other Kuiper Belt objects. Here’s Corwin Wray’s simulation (made with Pixel Gravity, his software for doing multi-body models on your laptop), which concludes with a wistful look back at our Solar System:
Like New Horizons, you can explore further too.
Itâs worth your while to start by tracking down Guy Ottewell. Yes, heâs on the web, folks, and you can connect with him! Start with his Home Page, which includes all of his books, including the latest version of the book form of his Thousand-Yard Model as well as innovative ideas in several fields, from voting systems to landscape design:   He has a Facebook Page on which heâs been more active as of 2014, sharing art and world news:   And he joined Twitter in 2013 and tweets regularly, especially on human-rights topics, which should interest anyone whoâs become aware of just how small our human community is in this huge universe: find him as simply @GuyOttewell on the tweet machine. A few of his books are available at Amazon, but take careâthe latest updates are best obtained by purchasing directly from the author.
Of course, you might want to follow some of informational links given in the workbook pdfâs for this project:
And of course we have an active mission beyond Pluto right now. It’s an APL project, so they have a great page on the program: http://pluto.jhuapl.edu/
The National Optical Astronomy Observatory presents Guy Ottewellâs original project description from 1989 online:
A wonderful collection of poems and quotes related to astronomy, gathered by Michele Stark, an astronomer with a wonderful page she created while lecturing in physics at the University of Michigan, Flint. l  Youâll also find astronomy labs sheâs created for non-majors interested in the field, under âOutreach and Educationâ
A relatively exhaustive listing of scale models in place around the worldâmost are designed for point-to-point driving or cycling tours, so scroll to the bottom portion of the list for walkable models, several of which are roughly on the same scale as that presented here. Check before you set outâsome of these installations were only temporary, as part of larger events and some are virtual (i.e., online). I would like to imagine astronomy fans travelling to all of them, as baseball fans travel to all the major-league parks.
The National Center for Earth and Space Scienceâs âVoyageâ program has a âsomewhatâ pricier scale model in Washington D.C. but also offers up lots of useful curriculum materials:Â Â http://voyagesolarsystem.org/Â Â Their program is fee-based, not by any means free, but it is very comprehensive and aims to involve parents, teachers, students, and their communities: http://journeythroughtheuniverse.org/home/home_default.html
You can keep track of the Voyager spacecraft in real time at http://voyager.jpl.nasa.gov/where/index.html  Theyâre in rapid motionâVoyager 1 is travelling at over 38 thousand miles per hour (over 17 km per second).
The Project Astro Notebook used to be sold as a huge expensive bulky (and still wonderful) binder. Soon, youâll be able download at least some portions in pdf format from the free government-sponsored education resources site eric.gov. However, for now your best bet is to buy the DVDâs at http://astrosociety.org/astroshop/index.php?p=product&id=577&parent=1
Why use a FIFA 4 or 5 ball? Well, the dimensions are good for it. But any similar-sized ball will do for this project…like the tennis-ball-patterned playground ball I have. Guy Ottewell likes to use a bowling ballâbut notes that itâs kind of heavy to lug around. http://www.achallenge.com/t-faq.aspx
If you need more reassurance that science and math are not only fun but also funny, visit http://www.xkcd.com (but do prescreen before sharing with studentsâthis webcomic does sometimes use âPG-13â language.
For the jacks ball, you can pick up a jacks set anywhere. Online (e.g., www.orientaltrading.com , theyâre often sold in party packs of a dozen sets. But any bouncy ball bigger than žâ and no bigger than 1â in diameter will do the trick.
If you decide to buy a playground ball or soccer ball online, locate an air pump before your shipment arrivesâtheyâre often shipped uninflated.
And if you buy on Amazon, be sure to sign up for smile.amazon.com first, so your purchases can support your favorite charity.
Last week on the tvweb, this happened: astronomer Derrick Pitts turned up once more on “The Late Late Show”. And even though science-loving Craig Ferguson has moved on to new horizons, Director Pitts stayed and showed Guest Host Wayne Brady how to make a comet. So I looked back at my entries for this project and realized they need some updates, and particularly some visuals. Have patience–it’s a multi-entry blog feature, so look for two more entries for the complete Updated Edition of “Cooking With Kuiper.”
The Kuiper Belt–that donut-shaped aggregation of hundreds-of-thousands of rocky objects orbiting beyond Neptune–is one of the most interesting regions of the Solar System just now. Just last year, NASA’s Deep Impact explorer hurled a probe into the surface of Comet Tempel 1, flinging up a curtain of debris to reveal more about the comet’s composition.
Deep Impact’s probe sent back this image just before striking Comet Tempel 1 (Image: NASA/JPL-Caltech/UMD)
NASA’s New Horizons mission is due to arrive in July 2015 at Pluto–the most famous Kuiper Belt object–to observe the newly-redesignated dwarf planet and its five moons and then head out to explore. You can check in on the progress of the mission at NASA’s home for New Horizons. There is a general agreement among astronomers that the comets which return again and again (periodic comets) began in the Kuiper belt.
In this project, we’ll be building a model of a comet using household supplies to represent most of the comet’s components and dry ice to capture the icy-cold environment of the Kuiper Belt.  While most Messy-Monday projects are entirely hands-on this particular activity is meant as a demonstration with controlled audience participation. Some students may be careful enough to work with dry iceâŚbut too many are not, and the step at which the dry ice is added can be dynamic and unpredictable.
A study of comets draws in much of what students should know about their planetary system and extends that knowledge into new and intriguing areas. Students in intermediate grades probably know the basics of cometsâŚthat they come from the far reaches of the solar system, that they have tails, and that a comet crashing into the earth makes a cool disaster movie. They might be surprised to know that scientists still want to find out more about comets, because all we know about comets so far is from watching them on their travels through the solar system. Just a few months ago, the Rosetta spacecraft launched in 2004 by the European Space Agency actually landed a robotic explorer named Philae on Comet Churyumov-Gerasimenko, so why not launch an investigation into the nature and structure of comets by building our own lumpy, irregular, gas-spewing comets?
This activity is best paired with at least one hands-on activity centering on comets.  The second activity in this series combines a crafting-style model construction project and a cometary motion simulation game. Other resources can provide other activities. For instance, students can make a flip-book illustrating a short-period cometâs behavior as it travels from the orbit of Neptune to the sun and back. And users of Pixel Gravity can run a simulation of the comet impact which led to the demise of the dinosaurs.
In the next installment, we’ll assemble a supply list for this project. I recommend you plan to build at least two comets, to let more kids participate and also to illustrate just how different two comets can be.
