by Bob Berman
Why do raisin-size stones amaze and entertain us when they hit our atmosphere and become hot rocks? Some of us might yawn during a lavish Broadway musical, but let nature hurl a pebble across the sky and everyone cheers. It's a reaction you, too, can enjoy come August 11, the night of the Perseid meteor shower.
Whether this annual show fizzles or sizzles depends almost entirely on the moon. Luckily, this year, unlike next year, our skies will be perfectly moonless on the night of the shower. In fact, for the first time in 38 years, the invisible new moon lands smack on meteor day. So even from a city rooftop--a less than ideal viewing post--you can watch a shooting star bisect the heavens every three or four minutes. For the best spectacle, of course, you'll need to get away from glaring city lights; few meteors shine brightly enough to stand out against a light-washed urban sky.
Don't worry: There won't be any mile-wide destroyers that can erase Earth's life-forms. Nor will we be disappointed by boring micrometeorites, which are so small that an astronaut's space suit can deflect them. (In any case, micrometeorites burn up in our atmosphere long before they become visible.) Instead we'll be treated to a mix of faint streaks and shadow-casting fireballs.
All of the Perseid meteors leap away from the northeast (the location of the constellation Perseus), but you'll be able to see them zipping throughout the heavens. A third of the meteors will be beautifully trailed by glowing dust, and at least 90 percent will travel superfast, zinging into our atmosphere at a blistering speed of 37 miles per second.
Few, if any, will make it to the ground. In 1992, a woman in Peekskill, New York, had her Chevrolet Malibu smashed by a meteor--but that rock was much hardier than the icy fragments scheduled to arrive this month. Back in 1996, early speculation falsely blamed the crash of TWA 800 on an incoming meteor. The real culprit was probably a fuel-tank explosion. If a meteor had been to blame, it wouldn't have been a fragment like the ones that populate this month's shower.
Perhaps because admission to this show is free, we tend to undervalue it. Even the laziest among us would set the alarm clock for the period of maximum intensity--between 1 and 5 a.m. on August 12--if the shower promised falling diamonds or exotic elements like antimatter. Instead, meteors contain things already found on Earth, so most of us stay in bed.
Not many such phenomena resonate so well with the human psyche. A full eclipse of the sun delivers a visceral impact. Saturn does it through a good telescope. And amazingly, all three appear this month. In fact, the millennium's final solar totality takes place on the same day as this last Perseid shower. The eclipse will cut a swath over Europe but won't be visible to North Americans. Thankfully, I've skirted the problem by scheduling a lecture in the moon's shadow on board a cruise ship in the Black Sea. Perhaps, in the suddenly darkened skies around the blacked-out sun, I'll be lucky enough to catch a passing shooting star. Of course, you don't need to be on a European vacation to appreciate August's show. These in-your-face dazzlers will be a thrilling spectacle anywhere.