The flyby of asteroid Annefrank came on November 2, 2002. Comet Wild 2 was visited on January 2, 2004. The comet Tempel 1 encounter occurred on February 14, 2011. Credit: NASA.

Stardust is the first spacecraft whose primary mission is to go to a comet and bring a piece of it back to Earth.

Comets are made of the stuff that formed the planets and hold many clues as to the formation of the solar system. These frozen balls of rock and ice are believed to have seeded the planets with water and organic molecules that could have sparked life on Earth.

In January 2004, Stardust rendezvoused with Comet Wild 2, snapping images of its nucleus and collecting dust samples.