Comets preserve important clues to the early history of the solar system, and may have also contributed some of the volatiles that make up our oceans and atmosphere. Comets may even have brought to Earth the complex molecules from which life arose.
|Woodcut showing destructive influence of a fourth century comet from Stanilaus Lubienietski's Theatrum Cometicum (Amsterdam, 1668) Don Yeomans' Comets: A Chronological History of Observation, Science, Myth and Folklore. Used with permission.|
Artist concept of original Stardust spacecraft showing sample return capsule.
Stardust-New Exploration of Tempel is a low-cost, low-risk mission that reuses the Stardust spacecraft, launched in February 1999, to flyby Comet Tempel 1 at a distance of 200 km on February 14, 2011 (39 days post perihelion) and obtain high-resolution images of the coma and nucleus, as well as measurements of the composition, size distribution and flux of dust emitted into the coma. The mission plans to expand the investigation of comet Tempel 1 initiated by the Deep Impact spacecraft in July 2004, and for the first time assess the
changes in the surface of a comet between two successive perihelion passages providing important new information on how Jupiter family (JF) comets evolve and how they were put together at their formation 4.6 billion years ago.
Our major aims are:
• To extend our understanding of the processes that affect the surfaces of comet nuclei by documenting the changes that have occurred on comet Tempel 1 between two successive perihelion passages.
• To characterize the crater produced by Deep Impact in July 2005 to better understand the structure and mechanical properties of cometary nuclei and elucidate crater formation processes in them.
|This image shows the composite ITS image of the nucleus with a grid or coordinate system laid over it. The grid helps the science team reference features on the surface. The positive pole is over the horizon at upper right and the longitudes increase according to the right hand rule as defined by the IAU convention. The prime meridian was defined to go through the center of the well-defined crater above the impact site.
CREDIT: NASA/UM/Cornell/Peter Thomas and Tony Farnham