Deep Impact on the 4th of July

Today, NASA's Deep Impact hit the comet Tempel 1 with a "smart" projectile to study the comet's composition, and the effects of the impact. Although this impact is not likely to divert the comet's path, it is exciting to think that 65 million years after the Yucatan impact, there are earthlings who might be able to prevent the next such threat to life on our little pale blue dot.