No master plan behind meteor flash
Joan and I were sitting in our hot tub Monday last week, staring up at the stars and wondering when — if ever — the rains would return to the B.C. interior, that day being our 66th without perceptible rainfall, when a brilliant flash lit up the eastern sky.
“Lightning?” Joan wondered. “The weather isn’t supposed to change until later this week.”
I started counting for the boom of thunder. Years ago, I learned that sound travels at roughly a thousand feet per second. If the boom follows the flash by five seconds, the centre of action is safely about a mile distant. (For a kilometre, about three seconds — a little closer.)
I quit counting after 10. Joan claims she heard a rumble, about 10 minutes later.
Which would be about right. Because the flash, we learned the next morning, had occurred more than 200 km away, directly over Kootenay Lake.
A hunk of rock left over from the formation of our solar system had smashed into the earth’s atmosphere over the little town of Boswell at the south end of Kootenay Lake; it blew up over Meadow Creek, slightly beyond the lake’s north end.
It blew up because it entered the upper reaches of the atmosphere at up to 250,000 km/h.
That’s about 10 times faster than a space shuttle’s re-entry. You may remember that overheating destroyed the Columbia shuttle, in 2003. Imagine the effect of an entry 10 times faster.
The sonic boom caused by its explosion shook houses in Kaslo and Nelson.
Technically, the flying rock was a meteoroid. If it burns up in the upper atmosphere, it’s called a bolide; colloquially, a “fireball.” It becomes a meteorite only if it survives long enough to hit the ground.
Jaymie Matthews, a professor of astronomy and astrophysics at the University of British Columbia, estimated that the meteoroid was about the size of a living room couch.
Alan Hildebrand, geoscience professor at the University of Calgary, estimated the couch’s weight at several tonnes.
If a mere flying couch can make that much bang and flash, I can only imagine what an asteroid 10 km in diameter would have done 66 million years ago, when it smashed into what’s now the Yucatan Peninsula in Mexico.
Apparently thousands of these space fragments hit the earth’s atmosphere every year. But few of them are seen. They’re too small to light up the sky. Especially during daylight hours. Or they arrive over under-populated regions like Canada’s far north. Or over the oceans, which cover three-quarters of the earth’s surface.
A fireball in the sky creates awe and wonder. A fireball that hits the earth causes fear and terror.
Especially if it smashes through a roof. Or hits a human being.
After natural disasters such as hurricanes Harvey and Irma, devastated victims wonder, “Why us? What did we do to deserve this?”
The dinosaurs might have asked themselves much the same question — if their minds were capable of formulating it — when their asteroid created a 180km crater.
Its fireball caused massive fires all over the world; the impact threw so much debris into the atmosphere that climate change killed off three-quarters of the earth’s species. Including those bemused dinosaurs. And what’s the answer? There isn’t one.
We humans don’t like to accept that things can happen by chance. We’re predisposed to believing in cause and effect.
Long before Isaac Newton formulated his Third Law of Motion — “For every action, there is an equal and opposite reaction” — our ancestors attempted to placate the gods of nature, hoping to ward off disasters like floods, earthquakes, volcanos, and hurricanes.
If things go wrong, we reason, we must have done something to deserve it. Or perhaps failed to do something, like offering enough sacrifices. Or prayers.
Modern science tells a different story. The universe is not a machine. We’re not dealing with cogs and gears. We’re dealing with probabilities. Among which is the infinitesimal probability of being hit by a meteorite. There is no master plan. There was no master plan to wipe out the dinosaurs.
There was no master plan to predestine that a particular chunk of rock, orbiting in empty space for five billion years since the formation of the solar system, should fall into the earth’s atmosphere at precisely 10:14 p.m. PDT on Monday, Sept. 4, to flash the length of Kootenay Lake before exploding so that a few of its meteorite fragments might fall into an unpopulated area and kill a specific earthworm in the forest floor.
There is no master plan. There are only probabilities. Which include chance.