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Detección de deuterio atómico en la atmósfera superior de Marte
V A Krasnopolsky1, M J Mumma, G R Gladstone
1Department of Physics, Catholic University of America, Washington, DC 20064, USA. VKras@lepvx3.gsfc.nasa.gov
Science (New York, N.Y.)
|June 11, 1998
Resumen
Marte Marte es el planeta Marte.
Área de la Ciencia:
- Ciencias planetarias Ciencias planetarias.
- Ciencias de la atmósfera Ciencias atmosféricas.
- La astroquímica es astroquímica.
Sus antecedentes:
- Comprender la composición atmosférica y la evolución de Marte es clave para su habitabilidad.
- Las proporciones de deuterio (hidrógeno pesado) a hidrógeno en el agua marciana y los gases atmosféricos proporcionan información sobre la pérdida de agua y los procesos atmosféricos.
Objetivo del estudio:
- Para medir la intensidad de la línea alfa Lyman de deuterio en la atmósfera de Marte.
- Para determinar la proporción de hidrógeno molecular (HD) unido al deuterio con hidrógeno molecular (H2).
- Para comparar la fraccionamiento HD/H2 con el del agua (HDO/H2O) y comprender los procesos atmosféricos marcianos.
Principales métodos:
- Utilizó espectroscopia de alta resolución con el Telescopio Espacial Hubble.
- Se midió la intensidad de la línea alfa de Lyman de deuterio en la atmósfera de Marte.
Principales resultados:
- Se ha detectado la línea de deuterio Lyman alfa a 23 +/- 6 rayleighs.
- Se calcula la relación HD/H2 como 1,5 +/- 0,6 x 10(-4).
- Se encontró que HD/H2 es 11 veces más pequeño que HDO/H2O, lo que indica un control termodinámico de la fraccionamiento.
Conclusiones:
- La fraccionamiento HD/H2 marciano está controlado termodinámicamente, no cinéticamente.
- El hidrógeno molecular (H2) se agota significativamente en el deuterio en comparación con el agua debido a su larga vida atmosférica.
- La fraccionamiento isotópico observado sugiere una reserva planetaria de hielo de agua intercambiable de aproximadamente 5 metros de espesor.
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