A Meteoric Rise

Good astronomy: Meteors don't rise. They fall.

First, what is a meteor? A meteoroid is any bit of detritus floating around in space, whose path intersects the Earth's. It becomes a meteor when it hits the Earth's atmosphere and burns up. If it impacts the ground, it's called a meteorite.

You can see many meteors on pretty much any clear night. The solar system is full of little bits of flotsam, and on a clear night from a nice dark site you can see two or three an hour. These are sporadic, or random, meteors. Many of these are thought to be leftover bits of asteroids, formed when asteroids impact and shatter. They tool around the solar system until something big gets in their way.

On some nights you can see many many more meteors. During a meteor shower, like the Perseid shower which peaks around August 13 every year, you can see as many as 60 or more an hour. One shower, the Leonids, which occurs in November every year, has superspurts: in 1799, 1833, 1866 and 1966 over 2000 meteors an hour were seen! For several minutes in the 1833 shower, over 200,000 meteors an hour were seen! No one is sure if these incredible performances will be repeated in 1999 or not. Keep your eyes open! Anyway, these meteors are associated with bits and pieces of comets that slough off as the comet orbits the Sun.

So meteors start off in space, and then fall to the Earth. They appear dramatically, flashing into out view, and burn out suddenly, sometimes leaving a long trail of glowing ash behind them.

I was reading a major metropolitan newspaper the other day, and it referred to a Russian official's "meteoric rise" in the political structure of that country. Of course, the reporter meant that the the official appeared out of nowhere and has made a quick, brilliant rise to the top of his heap. The real meaning of the phrase, however, is just the opposite: were we to be literal, the official would have made a sudden eye-catching appearance in the political arena and then quickly burned himself out. He may have left a trail behind him, and even made quite an impact in the end!

Bad Addendum: many people think that a meteorite, after it hits the ground, is very hot and glows red. Actually, meteorites found shortly after impact tend to be warm, but not hot at all! It turns out that it certainly is hot enough to glow while it is in the part of the atmosphere that decelerates it the strongest, but any part that actually melts will be blown off ("ablated") by the wind of its passage. That leaves only the warm part. Even more, the meteor is slowed down so strongly as it moves through the atmosphere that the impact speed is typically only a few hundred kilometers an hour at most. Only the very large (and we're talking meters across) meteors are still moving at thousands of kilometers an hour or more when they impact. Small ones aren't moving that fast at all. Not to say you'd want to be under one: a car in New York was struck by a small meteorite and had a hole punched through it, and the whole back end crushed in. Ouch!

Want to know more about meteors and meteor showers? Here are some links: