Well, the Pentagon did invent the Internet (and not Al Gore), so I think they're entitled to use it every so often. ;-) Whether you like it or not, MaryAnn, you owe the Pentagon and DARPA in some small way for laying the foundations that made it possible for there to be blogs in the first place.

The video is grainy because they were probably using a fairly small lens to shoot it, at night, and the image had to be digitally zoomed on top of all that. It's not like they were using the Hubble to track the missile in flight. (And it's more likely that after the missile was launched, they just started tracking the satellite with the camera, since it was moving in a sedate orbit.)

There was nothing to be done about the hydrazine tank onboard Columbia... the shuttle disintegrated without warning and any fuel it was carrying probably dissipated harmlessly into the atmosphere. But there's a difference here: This satellite's hydrazine tank was completely full, because the satellite couldn't be contacted immediately after it was launched, and it never burned even an ounce of fuel maneuvering. So we're talking about a much larger quantity of fuel, in a satellite that was intended to remain in orbit for years, not the week or two of a shuttle mission. Imagine that if this satellite were allowed to reenter on its own (and remember, they had no way of controlling where and when it would reenter, only if), and that parts of it came down in a populated area, and a tank full of hydrazine somehow survived... well, you can imagine that people would be unhappy about being exposed to that.

But you're correct that this was probably mostly about sending a message to the Chinese, the Europeans, and the Russians: We can shoot down satellites in fairly low orbits from virtually anywhere on the planet, so don't get any funny ideas. This spy satellite was in a low and degrading orbit, but it's not out of the realm of possibility that a similar missile could reach out as far as the orbits where navigation satellites live.

You might find this interesting:
http://www.badastronomy.com/bablog/2008/02/19/blowing-up-a-spy-satellite/
You might like the rest of the blog, too, if for no other reason that the Bad Astronomer is as much a Dr. Who fan as you.

Awesome. I figured you were familiar with his blog, geek goddess that you are, but I hadn't guessed you'ld met him personally. I myself have attended a couple of his science teacher workshops in California. Great guy - and my six degrees gets ever smaller. =)

"the Pentagon did invent the Internet (and not Al Gore)"
High Performance Computing and Communication Act of 1991 (often referred to as the Gore Bill) was initiated by Al Gore. As Vice President, Gore championed funding and private investment for the Advanced Research Projects Agency Network ARPANet- the world's first operational packet switching network, and the predecessor of the global Internet.
Its a little tiring to hear this old joke. He never really claimed to "invent it," and nobody ever believed he did. And this old claim helped get him defeated and got George W. elected. It still would have been less harmful than "weapons of mass destruction" claims. FU

Woo-hoo! You're all clear kid, now let's blow this thing and go home!