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Composiciones elementales del cometa 81P/Wild 2 muestras recolectadas por Stardust
George J Flynn1, Pierre Bleuet, Janet Borg
1Department of Physics, State University of New York at Plattsburgh, 101 Broad Street, Plattsburgh, NY 12901, USA. george.flynn@plattsburgh.edu
Science (New York, N.Y.)
|December 16, 2006
Resumen
Los datos de la misión Stardust revelan que las partículas del cometa 81P/Wild 2 son químicamente diversas. Su composición elemental se alinea con los modelos del sistema solar para la mayoría de los elementos, pero muestra enriquecimiento en cobre, zinc y galio.
Área de la Ciencia:
- Cosmoquímica es la cosmoquímica.
- Ciencias planetarias Ciencias planetarias.
- Ciencia de los Cometas Ciencia de los Cometas
Sus antecedentes:
- Los cometas son restos del sistema solar primitivo, ofreciendo información sobre su composición.
- La misión Stardust recogió muestras del cometa 81P/Wild 2 para analizar su material.
- Comprender la composición elemental de los cometas ayuda a refinar los modelos de la formación del sistema solar.
Objetivo del estudio:
- Para determinar la composición elemental de las partículas de polvo del cometa 81P/Wild 2.
- Para comparar la composición del material cometario con los modelos de composición del sistema solar existentes (meteoritos CI).
- Para identificar cualquier agotamiento o enriquecimiento elemental significativo en las muestras cometarias.
Principales métodos:
- Análisis de la composición elemental de 23 partículas atrapadas en aerogel y 7 residuos de cráter del cometa 81P/Wild 2.
- Utilizado material recogido por la nave espacial Stardust durante su paso a través del coma del cometa.
- Investigó la heterogeneidad química a una escala de aproximadamente 180 nanogramos.
Principales resultados:
- Las partículas cometarias exhiben una heterogeneidad química.
- La composición elemental media es consistente con la composición del meteorito CI para Mg, Si, Mn, Fe, Ni (dentro del 35%) y Ca, Ti (dentro del 60%).
- El cobre (Cu), el zinc (Zn) y el galio (Ga) se encuentran enriquecidos en el material Wild 2 en comparación con los meteoritos CI.
Conclusiones:
- El material cometario de 81P/Wild 2 proporciona una muestra única de material del sistema solar temprano.
- El enriquecimiento observado de Cu, Zn y Ga sugiere que los meteoritos CI pueden no representar con precisión la composición masiva del sistema solar para estos elementos menores moderadamente volátiles.
- Se necesitan más análisis para refinar nuestra comprensión de la abundancia de elementos moderadamente volátiles en el sistema solar.
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