This image shows a flash produced in a laboratory by a high-velocity bead
slamming into dust. Though the flash itself can't be resolved, its
brilliant effects can be seen in this three-second time exposure.
Scientists say that the collision between Deep Impact's impactor and
comet Tempel 1 may produce a similar flash.
This flash occurred when a quarter-inch sphere smashed into powdered dust
at a speed of 6.4 kilometers per second (4 miles per second). Even though
the actual flash lasted less than 50 millionths of a second, the camera
recorded the hot debris in the impact crater (center) and the streaking
ejecta. This experiment was performed at NASA's Ames Research Center,
Moffett Field, Calif.