Comet Wild 2, as imaged by NASA's Stardust spacecraft.

Well, at Chabot, we like to bring things down to Earth a bit—not to diminish their wonder and awe-inspiring beauty, but rather to give us a chance to connect with pieces of the Universe in a personal way that—we hope—will only enhance their wonder.

Such it is with the Personal Comet. We make them in our classrooms, and our teen volunteers—Galaxy Explorers—sometimes set up a table in our exhibits to make comets for our visitors.

Last week I was teaching a lively group of 3rd graders our class, "Shooting Stars" (I'm not the usual teacher for this class, but love teaching this one especially).

"Let's make a comet," I announced, receiving a classroomful of suddenly puzzled 8-year-old faces. "Follow me." I led the group to the back of the room and had them sit in front of our rolling comet kitchen, tying on an apron and donning the "Comet Chef" hat.

"What's in a comet?" I quizzed. Hands went up, and answers were plucked out. "Water." "Ice." "Very small pebbles."

"Good answers. Let's start cookin'…."

One by one, and two at a time, I called up volunteers (no lack of these at all) to add ingredients into the mixing bowl.

Water first—two cupfuls. What else? The Chef helped out his students a bit: pebbles are fine, but what are they?

Silicon, calcium, to name a couple—so we add a source of these: sand. Then, iron, and magnesium—two more known comet constituents. Source? Dirt! Dirt can contain these, among other things.

For the carbon in our comet, we added—carbon: black charcoal dust; just a dusting.

There is nitrogen mixed up in comets too, so we had to add some to our concoction. Our nitrogen source (other than all the gaseous nitrogen floating about us in the air) is ammonia—NH₃ (what's a little hydrogen in the compound, more or less? In fact, ammonia itself has been detected in comets, so our recipe is true).

Organic compounds—carbon based organic molecules—have also been detected in comets…so we add a couple glugs of corn syrup. Okay, that's cheating a bit, because comet organics aren't known to come from agricultural products….

And lastly, but not leastly, is the two-in-one ingredient: contained in a plastic bag, I had the class use mallets to pulverize a few cupfuls of dry ice pellets into a fine powder. This adds not only the carbon dioxide to the material makeup of the Personal Comet, but that which really makes the difference between a bowlful of slightly sweet mud and the astral nugget of a comet: COLD! Space is cold, and so is dry ice.
In goes the frigid, dry frost, and out erupts clouds of billowing vapor—very exciting stuff. Now the Chef had to work fast, stirring and mixing and shaking the brew, and then squeezing the convulsive mixture in its plastic bag, with gloved hands, into a hard, solid lump. It takes a lot of squeezing, as it turns out….

Is it done yet?

I pulled out of the bag our Personal Comet, holding it out for the kids to marvel at—and they did. The double-fist-sized, dirty whitish, somewhat gritty hard blob is covered with pits and knobs and spouting plumes vapor. And, magically, it looks almost identical to a photograph of the nucleus of comet Wild 2, taken by NASA's Stardust spacecraft some years ago.

Everyone got to touch the comet—quickly, because it was quite cold—and make a personal connection with a tiny piece of the heavens. Now, I think, these kids are armed with an experience that will make their first comet-observing experience (yet to come for many of them!) a bit deeper, as I hope when they do see the vastly awesome sight in the sky, or through the eyepiece of a telescope, they'll also remember what it's like to touch a comet, or smell a comet, or see one spouting vapor right before them, in the palm of their hand….

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QUEST Producer Chris Bauer rides into the hunt in the back of a pick-up truck.

"Oh, we’ll get letters."

I knew going into this story that we might ruffle some feathers. But one of the things that made this story so intriguing to me is that it would bring up some questions about where people stand on what can be a pretty touchy subject.

So full disclosure – I generally side myself on the side of environmentalists, naturalists and true scientists. I think extremism one way or the other is generally not a good idea. I believe in the overwhelming scientific evidence that global climate change is happening and human behavior is the root cause. I'm pro-open space. I like clean air and water. I support the restoration of native ecosystems. I champion native plants and animals. I am against pollution, invasive species and uncontrolled urban sprawl. Some things we judge for ourselves one side or the other. Such as, I am for native song birds and against feral cats. But some other things don’t tie up into a pretty package. For example, I love natural ecosystems but I am not ready to support clear-cutting the cypress trees in The Presidio. I'm not a hunter. But I eat meat. I may feel some pangs of guilt when I see an animal shot but those feelings are rarely there when I purchase meat at the grocery store. I like my barbecue. That’s me. (If you eat meat too, check out our great Quest radio story on Low-Carbon Diets and get a preview of the letters we’ll receive regarding this story.)

So where do you stand? And what happens if your stances are on opposite sides of the fence? Perhaps you are for clean energy and also happen to care for the native bird populations? See our story "Fatal Attraction: Birds and Wind Turbines."

Sometimes these questions can prompt us to examine what is truly most important to us. This brings me to the invasive pigs. There are people who are adamantly opposed to all hunting or any animal control. I can understand and respect their opinions. But many of those same people also consider themselves pro-environment. So is the thought of shooting a pig so distasteful that you are willing to sacrifice the native flora and fauna? What happens to the indigenous fox, deer, ground squirrel or California quail? Are you willing to give up California's live oaks, wildflowers and other native species that may be directly impacted by this invasive species? You can’t always have it both ways. Anyway…something to chew on.

Oh, and by the way… We'll get letters.

Watch the Hog Wild television story online.

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