Sometimes, in describing the natural world, our words rub against each other. The mind has to bridge a contradiction between what our eyes perceive and what is. The Perseid meteor shower, which peaks tonight, is a case in point.

A meteor is a speck of debris. But how can "debris" even be associated with what we call a shooting star? A shooting star is a surprise and a thrill, a sight to wish upon, a fleeting hint of the vastness and vivacity of the universe. Debris? Bah!

Unless clouds get in the way, which would be no surprise, it will not take a lucky glance to see a shooting star tonight. Especially after 2 a.m., when the first-quarter moon sets and night deepens, shooting stars will streak across the northeastern sky at 60 per hour or more. Even earlier, in moonlight but away from city light, it should be easy to see shooting stars.

Shooting stars are debris in this sense: When a comet passes through our solar system, it leaves a trail of grains of ice, dust and rock. As Earth orbits the sun, it passes through this trail of debris each summer. Some of the particles enter Earth's upper atmosphere and burn. We see them as streaking flames.

Especially when they are small and faint, shooting stars appear to be deep in the sky. In fact, they are less than a hundred miles up. Nearly all burn before they reach the air we breathe. The few that reach Earth are called meteorites.

The Perseids form the trail of a comet known as Swift-Tuttle, named after the American astronomers who detected it when it passed through our solar system in 1862. It made a return visit in 1992, and astronomers predict it will be back again in 2116.

Swift-Tuttle shed most of the particles you now see as shooting stars hundreds and perhaps thousands of years ago. But astronomers also say that Swift-Tuttle's 1862 passage left a great deal of debris.

All this science is irrelevant to what the mind perceives and the heart feels at the sight of a meteor. There are few moments so transporting, majestic or romantic. Seeing a shooting star, or tens of them, is an experience to cherish and to share.

If the weather does interfere with viewing tonight, there will be more chances to see meteors from the Perseid shower. It began in mid-July and ends its run on Aug. 24. Just find a dark place with a good view of the sky, lie on a blanket or lean back in a lawn chair and gaze north.