Quiet Before the Storm
This image shows comet Tempel 1 approximately 5 minutes before Deep Impact's probe smashed into its surface. It was taken by the probe's impactor targeting sensor. The Sun is to the right of the image and reveals terrain varying in brightness by a factor of two. Shadows and bright areas indicate surface topography. Smooth regions with no features (lower left and upper right) are probably younger than rougher areas with circular features, which are most likely impact craters. The probe crashed between the two dark-rimmed craters near the center and bottom of the comet.
The nucleus is estimated to be about 5 kilometers (3.1 miles) across and 7 (4.3 miles) kilometers tall.