Tuesday, August 14, 2012

Holy Shit, Meteors!

My wife and I spent several hours late Saturday night/early Sunday morning watching the Perseid meteor shower in our backyard. It got me thinking, "Holy shit, we're seeing chunks of rocks from SPACE, burning up to dust in our atmosphere. I mentioned the mind-boggling vastness of space before. It's really, really, really big. And yet, once a year, because the Swift-Tuttle Comet leaves behind a huge cloud of dust where the Earth goes, we get a reliable view of stuff burning up in our atmosphere. And that's just one of several annual meteor showers.

As it turns out, given how much empty space there is in the universe, there's also a shitload of debris. You can tell by looking at the moon. All those little dents you can see in the surface are from meteor strikes. Over the past few billion years, our neighbor has gathered quite a few of them. "But wait," said the rhetorical device, "If the moon gets hit so often, why don't we?" Well, Mr. Device, there are two answers to your question.

The first answer is that there are many much bigger objects with stronger gravitational pulls in the solar system that attract meteors that may otherwise hit us. Jupiter is the main one. I think we should take time every once in a while to thank Jupiter for that, because we'd probably be pretty dead if it didn't take one for the team so often. The moon helps, too, since it's so close. So thanks, Moon. Way to have your head in the game.

The second answer, though, is that we do get hit by meteors all the time. It's just harder to tell. There are craters caused by meteorites all over the planet, some of them huge. The big ones usually happen out of sight. An unexplained explosion the size of an atomic bomb in Tunguska in 1927 is attributed to a meteor or comet strike.

The small ones, though: all the time. We usually don't notice, but sometimes we do. Sometimes they hit someone's house. If you ever see a strange looking dark rock that's much heavier than other rocks of the same size, put a magnet up to it. If it sticks, you can say to yourself, "Self, this rock came from goddamn space."

Holy shit.

2 comments:

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  2. And the ocean! With a sizable portion of the Earth made up of water, it makes sense that many meteorites would hit the ocean, thus making them far less noticeable to us land-dwelling peons, amiright?!

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