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Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations
Published on: September 11, 2016
Evidencia de que la reactividad del suelo marciano se debe a los iones de superóxido
1Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA. Albert.Yen@jpl.nasa.gov
Science (New York, N.Y.)
|September 16, 2000
Resumen
El suelo de Marte es químicamente reactivo debido a los iones radicales de superóxido que se forman en las superficies minerales bajo la radiación UV. Esto explica la falta de material orgánico detectado por las Viking Landers.
Área de la Ciencia:
- Astrobiología Astrobiología.
- Ciencias planetarias Ciencias planetarias.
- La geoquímica es la geoquímica.
Sus antecedentes:
- Las Viking Landers detectaron suelo reactivo marciano, no vida, sino moléculas orgánicas en descomposición.
- Se planteó la hipótesis de que la reactividad provenía de superóxidos o peróxidos inorgánicos desconocidos.
- La ausencia de material orgánico superficial sigue siendo inexplicable.
Objetivo del estudio:
- Para investigar la fuente de la reactividad del suelo marciano.
- Para determinar si los iones radicales de superóxido podrían formarse en los minerales marcianos.
- Para explicar la descomposición de las moléculas orgánicas observadas por Viking.
Principales métodos:
- Se utilizó la espectroscopia de resonancia paramagnética de electrones.
- Superficies minerales análogas a las de Marte expuestas a condiciones atmosféricas marcianas simuladas.
- Superficies minerales irradiadas con radiación ultravioleta.
Principales resultados:
- Se observaron directamente la formación de iones radicales de superóxido (O2-) en las superficies minerales.
- La formación ocurrió bajo condiciones atmosféricas marcianas simuladas y exposición a rayos UV.
- Estos radicales demuestran un mecanismo para la reactividad del suelo.
Conclusiones:
- Los iones de radicales superóxido son una causa probable de la reactividad del suelo marciano.
- La presencia de estos radicales explica la descomposición de las moléculas orgánicas.
- Este hallazgo ofrece una explicación química para los resultados del Viking Lander.
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