Bad Astronomy

Rain of iron on Earth

Going through some articles on Digg, I noticed one with the unassuming title of Sikhote-Alin Meteorite. Regular readers here know I am a sucker for meteorites, and Sikhote-Alins are my favorites. I own several small ones.

So I clicked through to find myself on a blog called Black Holes and Stuff. This particular post was about the Sikhote-Alin meteorite fall that occurred in the old Soviet Union back in 1947. They are treasured by collectors for their beauty and unusual shapes.

To my delight, on that blog post I found an embedded YouTube video that’s a condensed version of an old Soviet documentary about the finding of the debris!

This is actually a pretty cool doco. I think I may have groaned out loud when they showed a worker finding a chunk bigger than his hand; it would be worth well over $10,000 today. Sikhote-Alin sells for $2/gram or more, and a chunk that size would easily have massed 2 - 3 kilos. At least.

The coolest part happens starting at 6:10 in the video, where they show a hole created by a falling chunk that’s drilled clear through a standing tree! Wow!

If you go outside at night and look up for an hour, chances are you’ll see the odd meteor or two. Those are usually chunks of rock or ice from comets, and they burn up high in the air. They’re small, maybe the size of a grain of sand or smaller. Pieces as big as Sikhote-Alin are very rare, falling to Earth only every few years or so, and most come in over water. It’s incredibly rare to have one come in over a populated area, so you don’t have to worry too much about meteorite insurance.

On the other hand, one big enough – say, 30 meters across – could wipe out a city. Those are really, really rare, of course, happening on the timescale of many millennia. But that’s a statistical occurrence. The next one might not hit for 100,000 years, or it may come in tonight.

That’s why I advocate keeping our eyes on these guys in the skies. On a small scale, rains of iron are really interesting. On a large scale, they can wipe out whole genera of life on the planet. That’s interesting, too, but more of a bummer.

Wanna learn more? Get my book, Death from the Skies! Chapter 1 is all about asteroid and comet impacts.