This image shows the tracks left by two comet particles after they impacted NASA's Stardust spacecraft's comet dust collector. The collector is made up of a low-density glass material called aerogel.

This image shows the tracks left by two comet particles after they impacted the Stardust spacecraft's comet dust collector. The collector is made up of a low-density glass material called aerogel. Scientists have begun extracting comet particles from these and other similar tadpole-shaped tracks.

View all Images