Monday, July 29, 2013

Should We Really Be Concerned About Asteroids?

Several blockbuster movies terrify us with an asteroid strike. Is that realistic or Hollywood fluff? I wasn't sure until I came across this passage in a book criticizing NASA plans to prioritize a manned mission to Mars and/or an asteroid:
"[NASA's Near-Earth Object Program Office in Pasadena] claims to have accounted for 60-90 percent of all civilization-wrecking objects, mostly asteroids, but only about 1,300 potentially hazardous asteroids have actually be [sic] catalogued so far. These objects are at least five hundred feet in diameter and pass within 0.05 AU (about 4.65 million miles) of Earth. However, the number of NEOs [near earth objects] increases sharply as their size decreases. We are more likely to be hit by something too small and moving too fast to be detected in time to knock it off course. People in the path of the object, like those living along the path of a hurricane, would have to be warned and evacuated beforehand.
Recall, too, that the Earth is 70 percent water and that we inhabit less than 1 percent of its surface, mostly along coastlines. In the worst case, the next big meteoroid event would resemble the 2004 Indonesian earthquake and tsunami that killed 230,000 people [note that this number is much higher than it would have been in a country with more developed infrastructure and buildings]. If NEO control officers stay alert, we should have time to move people out of the way and prevent mass casualties. On the whole, it seems more sensible to worry about a terrorist with a suitcase bomb or a deadly global pandemic than about being hit by a massive space rock."
Mankind Beyond Earth by Claude A. Piantadosi (published 2012), page 222. [Emphasis mine.]
I didn't consider an asteroid strike as a disaster threat until I read the novella An L.A. Asteroid Impact. The ebook uses a story to introduce and discuss the "bug out bag." Personally, I find the idea awesome, really concretizing the ideas. But don't think this is Shakespeare; it's certainly not. The premise is that a fictional couple gets 15 minutes notice that small asteroid is about to strike somewhere in the Los Angeles area. Thankfully, they're together, at home, and luckily happen to be watching the news at the time of the public announcement. I thought this seemed like a really far-fetched idea even before you consider the lucky coincidences just mentioned. Fifteen minutes notice for an asteroid over a major American city? That's ridiculous. Well, it's not so ridiculous anymore.

I'll admit I wasn't paying much attention when a much-publicized asteroid struck Russia earlier this year. I knew it happened, I saw the videos, and I even learned why there were so many videos of it, but I never stopped to think about the implications. Who wants to think very hard about that? An asteroid. Hit. Earth. A populated area. NASA was prepared for another asteroid pass that day, but totally missed this one. (Have to love the title of the NASA article: What Exploded over Russia?) If you were a Russian on that day, what would you have thought it was? How would you have reacted?

Here is NASA's cheery last thought on the subject:
"Preliminary reports, mainly communicated through the media, suggest that the asteroid was made mostly of stone with a bit of iron--'in other words, a typical asteroid from beyond the orbit of Mars,' says Cooke. 'There are millions more just like it.'
 And that is something to think about as the cleanup in Chelyabinsk continues."
While an asteroid strike may seem (and hopefully is) quite remote, it should not be ignored. Thankfully, as asteroid evacuation alert would be treated like any other evacuation alert, but don't let the subject matter of the evacuation make you freeze. Or disbelieve it because it seems ridiculous.

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