Deep Impact: excavating comet Tempel 1.
Deep Impact collided with comet Tempel 1, excavating a crater controlled by gravity. The comet's outer layer is composed of 1- to 100-micrometer fine particles with negligible strength (<65 pascals). Local gravitational field and average nucleus density (600 kilograms per cubic meter) are estimated from ejecta fallback. Initial ejecta were hot (>1000 kelvins). A large increase in organic material occurred during and after the event, with smaller changes in carbon dioxide relative to water. On approach, the spacecraft observed frequent natural outbursts, a mean radius of 3.0 +/- 0.1 kilometers, smooth and rough terrain, scarps, and impact craters. A thermal map indicates a surface in equilibrium with sunlight.
A'Hearn
M F
MF
University of Maryland, College Park, MD 20742, USA. ma@astro.umd.edu
Belton
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MJ
Delamere
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Kissel
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Klaasen
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McFadden
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Meech
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Melosh
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Schultz
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Sunshine
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Thomas
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Veverka
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Yeomans
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Baca
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Busko
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Crockett
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Collins
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Desnoyer
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Eberhardy
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Ernst
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Farnham
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Feaga
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Groussin
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Hampton
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Ipatov
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Lindler
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Lisse
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Mastrodemos
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Owen
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Richardson
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Wellnitz
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White
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D018538:Jupiter; D019110:Meteoroids; D009930:Organic Chemicals / Q000032:analysis; D013057:Spectrum Analysis
D009930:Organic Chemicals