Cometary Dust Unveiled

When the Sun heats the surface of a comet's nucleus, dust particles are released that contain the most primitive matter in the solar system. In her Perspective, [Levasseur-Regourd][1] discusses results from the Stardust mission to Comet Wild 2, published in the same issue, in which swarms of dust particles were observed. The images show striking variations in the flux of dust particles over small length scales that may signal the breakup of aggregates within the nucleus. Understanding these processes, and the dust-particle size distributions that will be brought back in the later stages of the mission, may help us better solve the puzzle of whether water and organic material were carried to early Earth by comets. [1]: http://www.sciencemag.org/cgi/content/full/304/5678/1762