Day 72: Galaxies of salt and other stellar teaching moments from Huntsville, Alabama

Spiral galaxy (NGC 3370)

Well, I tried to take an evening off! After checking out the Great Moonbuggy Race at the U.S. Space & Rocket Center in Huntsville yesterday, I drove just out of town to Monte Sano State Park. The website advertised trails and primitive camp spots — all I needed, I thought, to stop thinking and writing about science for just a few hours, and relax. 

The dog and I set up our tent, enjoying the happy sounds of a very large boyscout troop camping nearby. Then we wandered off to check out some trails, and that’s when I saw the sign: “Planetarium show, 7:30 Saturday night.” I hadn’t even known there was a planetarium up there! And so of course, a couple hours later, I was sitting under a dome at the Von Braun Astronomical Society’s modest mountaintop digs, learning some basic astronomy alongside a hundred or more visitors of all ages, including ample representation from the scouts.

Barred spiral galaxy (NGC 1300)

After writing a handful of stories about the International Year of Astronomy 2009, it was neat to see a sign about the global event atop a wooded little mountain in Alabama. And after writing countless stories about bizarre celestial phenomena and the blurred edges of astronomy theory, it felt great to experience a refresher course on the basics of stars and galaxies.

Best of all, I got to tuck away some fantastic teaching methods. Brenda Rogers passed out white chalk and black construction paper, so the kids could draw four common galaxy types: spiral, barred spiral, elliptical and irregular. She held hands with 10 young volunteers in a circle, then arranged them in loose formation and all squished together, to drive home the difference between open and globular star clusters.

And she made up a great analogy to explain the numbers of stars in galaxies.

Elliptical, or egg-shaped, galaxy (NGC 1316)

Each pound of salt contains about 10 million grains, she learned from a company rep (she actually called Morton!). So it would take 20,000 pounds of salt, she explained, hoisting the tubular cardboard box, to make a smallish galaxy with 200 billion stars.

She had the children pour little cups of salt on black cloth on the floor, with an extra-large pile in the center to represent the galactic bulge, and thick swirls for the arms.

Irregular galaxy (IRAS 19115-2124, aka the Bird Galaxy)

I’ll bet Rogers’ methods worked wonders for the future little astronomers in the room; I learned well even as a spectator. The dome show lasted about an hour, followed by a viewing from the observatory telescope.

If you ever happen to be in the Huntsville area, the Von Braun Astronomical Society would be a great side trip. Make it a star-studded weekend, with a tour of the U.S. Space & Rocket Center, then a Saturday night on the mountain! (If camping isn’t your thing, Monte Sano offers plenty of other options.)