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Un ciclo orbital de hielo de agua en el cometa 67P a partir de cambios de color
Gianrico Filacchione1, Fabrizio Capaccioni2, Mauro Ciarniello2
1INAF-IAPS, Institute for Space Astrophysics and Planetology, Rome, Italy. gianrico.filacchione@inaf.it.
Nature
|February 7, 2020
Resumen
El cometa 67P/Churyumov-Gerasimenko exhibe cambios de color estacionales opuestos en su superficie y en su coma. El polvo rico en orgánico enrojece el coma, mientras que el hielo expuesto azula la superficie del núcleo durante el paso del perihelio.
Área de la Ciencia:
- Ciencias planetarias
- Ciencia de los cometas
- Astroquímica
Sus antecedentes:
- La actividad cometaria es impulsada por el calentamiento solar, lo que lleva a la liberación de gases y la eyección de polvo.
- Las propiedades del coma y el núcleo de los cometas evolucionan dinámicamente a lo largo de una órbita.
- El color de las partículas de polvo varía según la composición (orgánica, silicato, hielo de agua) y el tamaño del grano.
Objetivo del estudio:
- Para observar y analizar los ciclos de color estacionales en la superficie y el coma del cometa 67P/Churyumov-Gerasimenko.
- Investigar la relación entre el calor solar, la composición del polvo y los cambios de color observados.
Principales métodos:
- Análisis espectral de las observaciones del cometa 67P/Churyumov-Gerasimenko.
- Monitoreo de las variaciones de color en el coma y en la superficie del núcleo a través del paso del perihelio.
Principales resultados:
- Se observaron dos ciclos de color estacionales opuestos en el coma y en el núcleo.
- Enrojecimiento de coma atribuido al enriquecimiento de material orgánico submicrométrico y granos de carbono amorfo.
- La superficie del núcleo mostró tonos más azules debido a la exposición de capas de hielo prístino a medida que se eliminaba el polvo.
Conclusiones:
- La composición del polvo cometario y el tamaño del grano influyen significativamente en el color del coma.
- Los cambios estacionales revelan una interacción dinámica entre la eliminación del polvo, la sublimación del hielo y la evolución de la superficie.
- Lejos del Sol, la deshidratación de la superficie y la redeposición del polvo reducen la abundancia de hielo de agua y el enrojecimiento del coma.
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