Like a bullet hitting a bullet, is how NASA described its attempt to cause a hyperspeed collision between a probe and a comet. Read more about this below the video player.

July 1, 2005—NASA's Deep Impact spacecraft planned to launch a projectile into the surface of comet Tempel 1 on July 4, possibly causing the most spectacular fireworks on U.S. Independence Day.

The washing machine-size probe was to be deliberately placed into the path of the comet, which is half the size of Manhattan, for a collision at 23,000 miles per hour (37,000 kilometers per hour). The object of the exercise? To make a big hole in the comet and cause a giant cloud of ice and dust so that scientists can better understand what comets are made of. The experiment could also be useful should it ever be necessary to try to deflect a comet or some other large rock headed toward Earth.

This video news report presents the background and preparation for the mission.

Read the accompanying news story.

Click on the Photo in the News showing images of the impact.