Dec 15 2006
From The Space Library
Scientists who had examined comet samples collected by NASA’s Stardust spacecraft published research challenging currently held theories regarding comets and the solar system. Scientists believe that comets are ancient archives of relatively pristine material surviving from the solar system’s inception. Therefore, they study comets to glean information about the solar system’s formation. NASA had originally launched Stardust in 1999. In January 2004, the spacecraft had obtained particle samples from the comet Wild 2, returning the samples to Earth in January 2006.
Over 180 scientists had subsequently analyzed the particle samples, which had revealed a mixture of minerals from across the solar system. The discovery had challenged the prevailing idea that comets had formed in isolation, in the solar system’s outer fringes. The particle samples contained material that derived from the inner solar system, raising questions about how the material had reached the solar system’s far edge, and about how the solar system had formed. Moreover, Wild 2’s compositional material suggested that comets are of different types. The comet’s mélange of materials was different from the matter composing the comet Tempel 1, which NASA had analyzed in 2005, using its Deep Impact spacecraft. Researchers had found that Tempel 1 was largely composed of ice and dust.
Warren E. Leary, “Researchers Find Surprise in Makeup of a Comet,” New York Times, 15 December 2006; Joanne Baker, “Look into the Seeds of Time,” Science 314, no. 5806 (15 December 2006): 1707, http://www.sciencemag.org/cgi/content/summary/314/5806/1707 (DOI 10.1126/science.314.5806.1707; accessed 8 June 2010).
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