This week, Science publishes the first look at lab results from samples of a comet, brought back to Earth by the Stardust space probe after a round-trip journey of more than two billion miles. In Science, a Research Article and six Reports examine the physical, chemical, and minerological characteristics of the comet sample from a variety of viewpoints. Meanwhile, two Perspectives discuss how the NASA mission brought pieces of a comet back to Earth -- and what those pieces can tell us about the history of the solar system. An online video presentation accompanies the issue.

In Science

INTRODUCTION Look into the Seeds of Time  J. Baker PERSPECTIVES Whence Comets?  M. F. A'Hearn NASA Returns Rocks from a Comet  D. S. Burnett RESEARCH Article Comet 81P/Wild 2 Under a Microscope  D. Brownlee et al. REPORTS Impact Features on Stardust: Implications for Comet 81P/Wild 2 Dust  F. Hörz et al. Organics Captured from Comet 81P/Wild 2 by the Stardust Spacecraft  S. A. Sandford et al. Isotopic Compositions of Cometary Matter Returned by Stardust  K. D. McKeegan et al. Infrared Spectroscopy of Comet 81P/Wild 2 Samples Returned by Stardust  L. P. Keller et al. Elemental Compositions of Comet 81P/Wild 2 Samples Collected by Stardust  G. J. Flynn et al. Mineralogy and Petrology of Comet 81P/Wild 2 Nucleus Samples  M. E. Zolensky et al.

ONLINE THIS WEEK: Video In a video presentation, Stardust scientist Larry Nittler of the Carnegie Institution and Deep Impact investigator Lucy McFadden of the University of Maryland talk about the Stardust results and their implications for understanding the history of the solar system. (Flash 8 or higher required.)