Somehow I’d think this would be bigger news, or have I just not been paying close enough attention?

You can learn something about a rock by looking at it. But what most geologists really want is to smack it with a hammer.

And that’s just what planetary scientists will do July 4 when NASA’s Deep Impact mission reaches the comet Tempel 1 after a trip of six months and 80 million miles.

If all goes well, an 820-pound copper “hammer” the size of a bathtub will separate from its mother ship and, 24 hours later, smash into the comet’s icy nucleus at about 23,000 mph.

The Baltimore Sun: The Earth Strikes Back

(via Corridor of Madness)