When the night sky provides free entertainment

 

One night this August, my husband Richard and I woke at 3:30 am and headed groggily outside to our back deck to watch for meteors. As I stepped out the door, Richard said, "There’s one!" I looked overhead and caught the tail end of a white line fading in the black sky over our small town in south-central Colorado.

The meteor shower we roused ourselves to watch was the Perseids, the most reliable shower of the year, which begins in late July and peaks the second week of August before tapering off. This celestial drizzle of shooting stars is named for the constellation Perseus since the meteors seem to radiate outward from its location near the Milky Way.

The source of the falling stars is not the constellation, however, but a trail of dust laid down by Comet Swift-Tuttle. Earth passes through this debris-laden plume each summer, producing fireballs that streak across the heavens.

Comets are celestial construction junk, writes astronomer Chet Raymo, giant snowballs of ice and space debris left over from the formation of our solar system. They hang out in the fringes of our neighborhood until dislodged by passing stars and sent hurtling on pendulum-like orbital paths around the sun.

I curled up on the chaise lounge Richard had unfolded next to his and scanned the night sky, too dazzled by the abundant stars to notice meteors. As I began to pick out the familiar shapes of constellations, I was reminded of how lucky I am to live in the rural West, where the heavens remain dark, relatively unbleached by light pollution.

Soon, a meteor zipped across the hazy band of the Milky Way before burning out; an instant later, another whipped away in the opposite direction, leaving a straight and faintly reddish trail. After a few minutes with no meteor activity, a really bright one streaked halfway across the sky before vanishing in darkness.

Meteors begin as bits of debris left behind by a comet on its swing through our solar system. The sun boils the outer layers of the comet’s icy nucleus into a halo of shimmering gases; solar winds whip the debris into a streamlined "tail."

This powdery tail persists like the plume of dust trailing behind a pickup on a dirt road — except the comet-detritus is not as harmless as rural dust; in the zero gravity of space it never dissipates.

When earth passes through this trail of floating comet trash, bits of debris collide with our planet’s atmosphere. Heated instantly by the friction of their sudden encounter with gaseous air, the particles — most no bigger than a sand grain — flare as they shoot across the heavens, and are vaporized, all in less time than it takes to read this sentence.

The Perseid meteor shower can be counted on to produce a trickle of fiery comet-debris each summer. And in years when Earth brushes through a particularly dense portion of Comet Swift-Tuttle’s gritty plume, the trickle turns to a shower.

Humans have long read portents in such stellar rains, interpreting meteor showers as mythical beings like dragons or angels bearing messages from the heavens. One cannot help but be awed and a little bit frightened when it appears as if stars flare and fall.

If a meteor is large enough to survive its plunge through our atmosphere, the celestial detritus is dangerous indeed. Meteors have crashed through roofs, started forest fires, even killed people.

As Richard and I watched the bright streaks cross the star-freckled sky in the chill of night, I shivered, thinking of the skies over Iraq, where the artificial shooting stars of missiles and bombs split the darkness, their explosive tracings cruel imitations of meteors’ stunning beauty and deadly potential.

My small town in the Upper Arkansas River Valley is a long way from war-torn Iraq. But meteor showers bring that violence close in a way television images and news stories cannot. When our planet brushes across a debris-laden comet trail, sending flaming projectiles cascading in all directions, I can almost feel the searing power of those streaks of light. They provide evidence of something we usually cannot grasp: our own fragility in the course of Earth’s hurtling journey through space. In the momentary illumination as meteors flare in the night skies over my small town, the immensity of the universe seems very real, and our lives very brief and blessed indeed.

Susan Tweit is a contributor to Writers on the Range, a service of High Country News (hcn.org). She writes books and essays in Salida, Colorado.

Note: the opinions expressed in this column are those of the writer and do not necessarily reflect those of High Country News, its board or staff. If you'd like to share an opinion piece of your own, please write Betsy Marston at [email protected].

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