The Art of Seeing for Yourself

The Art of Seeing for Yourself

by Adam Frank for McGraw-Hill

"Ohhhhhhhhh!"

"Wow! That one was fast!"

"Oh man!"

"Look at that one! Did you see the tail! It was green. Really, it was bright green!"

"Dang, that one was so sweet!"

It was 4:30 am. My family was bleary eyed and bundled up against the early morning cold. Huddled on lawn chairs on a hill far from the city lights, we were yawning so wide you could drive a SUV down our throats. We were up early and out for an astronomical adventure. This night (Nov 19) was to be the peak of the Leonid meteor shower and we had dragged our sorry butts out of warm beds to catch a sky show that you can't reproduce with Lasers or even Hollywood special effects. It was the real thing, right above our heads.

Now before I go any further with this story I have to tell you a secret. I had never seen a meteor shower before this early, early morning. Yes, it is sad to admit that after a lifetime of loving astronomy, after a six year pursuit of a Ph.D. in astrophysics, after 10 years as a professional astronomer, I somehow had never actually seen anything like this before. Of course I could explain this egregious lack of experience by saying that I am a THEORETICAL astrophysicist. That means I am perfectly happy staying inside, doing math and never actually looking up at the real sky. Unfortunately that is a lame excuse.

Science, like art, should always begin with experience, not ideas. The wide, dark canopy of a clear sky in the chill of the night's small hours is not something for which you can write an equation. So there I was, watching the Leonids with my kids, my eyes popping out of my head and my jaw hanging by my knees.

Meteor showers occur when the Earth passes through the debris trail left by a passing comet. Comets, as you may have learned, are mountain sized "dirty iceballs" that traverse the solar system on cigar shaped elliptical orbits. As comets dive inward towards the Sun they heat up. Their outer layers become unstable and begin breaking up, throwing out pieces of rock into space. If the comet's trail cuts directly across the Earth's orbital path then later in the year, when the Earth reaches the intersection point, our planet will run straight into this swarm of comet-debris. As the Earth cuts through the debris-trail our outer atmosphere serves as a protective blanket from collisions. The vast majority of rocks hitting the Earth burn up. The friction that comes from rocketing through air molecules in Earth's upper atmosphere reduces the comet debris to cinders and dust. The bright trail we see from a meteor comes from the heated debris as well as light emitted by heated air molecules.

Of course meteors happen all the time and you may see one on any night. On the night of a meteor shower, however they just keep coming. During an intense shower as many as a few meteors per minute can be seen. What makes the show particularly cool to watch is the fact that most meteors appear to come from the same point in the sky (which they do since that is the direction of the comet debris trail). The Leonids get their name because this vertex of meteor trails (called the radiant) is in the constellation Leo.

That is all the theory I will give you for now because words can't do justice to actually being out there that cold morning. They moved so darn fast across the sky. And the colors in the trails glowed so bright and then were gone in an instant. Each meteor was so essentially fleeting. Like a dream you can almost remember you had to tell yourself, "Yes, I really did see it."

Science like art begins with experience. I can now tell you from my own that you need to get out of the classroom. Stay up late or get up early. Get away from the city. This is the "real world" and if you are awake for its subtle pleasures and gifts it will grace your life with more than just knowledge. What else is an education really about?

By the way…the next meteor shower are Lyrids in mid-April.

Check Out This Websites

American Meteor Society:
http://www.amsmeteors.org/index.html