Document Detail

Early inner solar system impactors: physical properties of comet nuclei and dust particles revisited.
MedLine Citation:
PMID:  17120128     Owner:  NLM     Status:  MEDLINE    
During the epoch of early bombardment, terrestrial planets have been heavily impacted by cometary nuclei and cometary dust particles progressively injected in the interplanetary medium. Stardust and Deep Impact missions confirm that the nuclei are porous, loosely consolidated objects, with densities below 1,000 kg m(-3), and that they often release small fragments of ices and dust. Recent numerical simulations of the light scattering properties of cometary dust particles indicate that they are highly porous, most likely fractal, and rich in absorbing organics compounds (with a mixture ratio of e.g. 33 to 60% in mass for comet Hale-Bopp). Taking into account the fact that porous structures survive more easily than compact ones during atmospheric entry, such results reinforce the scenario of the early terrestrial planets enrichment--in organics needed for life to originate--by comets.
A C Levasseur-Regourd; J Lasue; E Desvoivres
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Origins of life and evolution of the biosphere : the journal of the International Society for the Study of the Origin of Life     Volume:  36     ISSN:  0169-6149     ISO Abbreviation:  Orig Life Evol Biosph     Publication Date:  2006 Dec 
Date Detail:
Created Date:  2007-01-19     Completed Date:  2007-11-13     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8610391     Medline TA:  Orig Life Evol Biosph     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  507-14     Citation Subset:  IM; S    
Aéronomie CNRS-IPSL, Université Pierre et Marie Curie-Paris 6, UMR 7620, Route des Gâtines, BP 3, 91371 Verrières, France.
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MeSH Terms
Cosmic Dust*
Evolution, Planetary
Extraterrestrial Environment / chemistry*
Solar System*
Time Factors
Reg. No./Substance:
0/Cosmic Dust

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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