Incoming Asteroid? Bruce Willis Will Stop It!


This information comes second hand from the ever readible CalgaryGrit. In a recent article, he discusses the tough choices the Liberal government must make when it comes to deciding whether or not to sign onto the Bush Administration’s missile defence plan.

The debate threatens to split the Liberal party (albeit just on this one issue). Paul Martin has tried to placate both sides by speaking in favour of living up to Canada’s NORAD agreements, while at the same time promising that the missile defence program does not mean the “weaponization of space”.

Now that Bush raised the issue during his state visit, the debate is getting more intense. The Quebec wing of the Liberal party passed a resolution calling on the government to oppose missile defence. And, here’s the kicker: CalgaryGrit reports that Liberal MP Derek Lee spoke on CBC Radio’s Politics show favouring the weaponization of space because:

“We might need to stop one of those meteorites.”

Where do I begin?

The Bush Administration’s missile defence program will, at first, be composed primarily of anti-ballistic missiles placed along the Pacific coast and possibly the Canadian Arctic in order to stop missiles coming in from (likely candidates) North Korea and China. If this defence shield is extended into space, satellites with lasers or rail guns or ballistic missiles of their own will track incoming missiles and destroy them before they reach the ground.

So, those space-based anti-missile platforms will be staring down at the Earth, not out into space.

And in terms of using the missile defence shield to destroy incoming asteroids, I’d like to point Mr. Lee to the Bad Astronomy Website in general, and his thorough frisking of the bad science in the movie Armageddon in particular. It is possible to deflect asteroids and comets from striking the Earth, but only if said asteroid and comet were detected more than a year or two before impact, and really, really, really big missiles sent to deflect the thing while it is still several hundred million miles away.

Here’s a quote from Bad Astronomy:

(Bad Science)
In the opening sequence, we see an asteroid headed for Earth, and are told that this was the Dinosaur Killer 65 million years ago. The narrator says that it exploded with the force of “10,000 nuclear weapons”.

(Real Science)
10,000? Where did that number come from? If we assume the asteroid that impacted was 10 kilometers across (a typical number used for the impactor) and moving at 11 kilometers per second (which is actually a minimum speed; it almost has to be traveling faster than that) the impact should release something like 80,000,000 megatons of energy. Hello. Even if we assume a 100 megaton bomb, which is comfortably larger than any nuclear (device) ever detonated, that’s eight hundred thousand nuclear weapons! And remember, I rounded down a lot. If the velocity is higher, that number increases. [Note added January 14, 2002: I found a press release about the dinosaur killer impact impact that said the energy released was 10,000 times the world’s nuclear arsenal, which is in fair agreement with my calculation above, and shows again that the movie was way off.]

Asteroids likely to be defeated by the missile defence shield would also likely be defeated by our atmosphere.

Derek Lee’s comments amount to one of the lamest excuses for the missile defence shield on record.

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