Deep Impact
6.28.2005
On the 4th of July, a NASA spacecraft will blast a hole in Comet Tempel 1.
June 28, 2005: For the last five billion years of our planet's violent history, Earth has been walloped by comets. These small bodies and their asteroid cousins whacked Earth often in its early years, knocking the stuffing out of our young world. As the solar system matured, impacts happened less often?but they have never ceased. Earth bears its scars in the form of weathered craters and extinct species.
This 4th of July is payback time. For the first time in history, Earth gets to strike back.
The weapon: a NASA spacecraft named Deep Impact.
The target: a 10-mile wide comet named Tempel 1
Details here