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Variación del isótopo de oxígeno en los meteoritos de hierro y piedra
R C Greenwood1, I A Franchi, A Jambon
1Planetary and Space Sciences Research Institute, Open University, Walton Hall, Milton Keynes, MK7 6AA UK. r.c.greenwood@open.ac.uk
Science (New York, N.Y.)
|August 26, 2006
Resumen
Los meteoritos de piedra y hierro revelan orígenes asteroidales distintos. Las pallasitas y mesosideritas del grupo principal, originadas en cuerpos madre separados, ofrecen información sobre la formación planetaria temprana y la intensa deformación de asteroides.
Área de la Ciencia:
- Ciencias planetarias Ciencias planetarias.
- Cosmoquímica es la cosmoquímica.
- La meteorología es meteorítica.
Sus antecedentes:
- Los meteoritos, restos de la formación planetaria temprana, proporcionan datos cruciales sobre la evolución de los asteroides.
- Los meteoritos de hierro-piedra, que comprenden el grupo principal de palasitas y mesosideritas, representan muestras únicas de interiores de asteroides.
Objetivo del estudio:
- Investigar los orígenes asteroidales de las palasitas y mesosideritas del grupo principal utilizando análisis de isótopos de oxígeno de alta precisión.
- Determinar si estos grupos de meteoritos se originan en fuentes asteroidales distintas y su relación con otras clases de meteoritos.
Principales métodos:
- Se realizaron análisis de isótopos de oxígeno de alta precisión en muestras de pallasitas y mesosideritas del grupo principal.
- Los datos isotópicos se compararon con grupos de meteoritos conocidos, incluido el clan howardita-eucrita-diogenita (HED).
Principales resultados:
- Las mesosideritas son isotópicamente idénticas al clan HED, lo que sugiere un origen común, probablemente del asteroide 4 Vesta.
- Las pallasitas del grupo principal exhiben composiciones isotópicas únicas, lo que indica la derivación de un cuerpo madre distinto y perturbado.
- Estos meteoritos muestran evidencia de una significativa deformación de asteroides durante el inicio del Sistema Solar.
Conclusiones:
- Las pallasitas y mesosideritas del grupo principal se originan en fuentes asteroidales separadas, lo que pone de relieve la diversidad de los primeros cuerpos planetarios.
- Los hallazgos apoyan la hipótesis de que las mesosideritas están relacionadas con el asteroide Vesta.
- Los meteoritos de piedra y hierro subrayan los procesos dinámicos, incluida la deformación intensa, que ocurrieron durante la acreción planetaria.
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