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Imágenes de radar de Mercurio: evidencia para el hielo polar
Science (New York, N.Y.)
|October 23, 1992
Resumen
La cartografía por radar de Mercurio reveló una región polar altamente reflectante, lo que sugiere la presencia de hielo. Este hallazgo, observado utilizando tecnología de radar avanzada, ofrece nuevos conocimientos sobre la composición de la superficie de Mercurio.
Área de la Ciencia:
- Ciencias planetarias Ciencias planetarias.
- La radioastronomía es una radioastronomía.
- La geofísica es la geofísica.
Sus antecedentes:
- La composición de la superficie de Mercurio sigue siendo incompletamente entendida, particularmente las regiones no mapeadas por misiones anteriores.
- Las observaciones por radar ofrecen un método único para sondear las superficies planetarias, incluida la composición y la topografía.
Objetivo del estudio:
- Para llevar a cabo la primera cartografía inequívoca de radar de disco completo de Mercurio.
- Para investigar el hemisferio no fotografiado de Mercurio utilizando el radar.
- Para buscar evidencia de volátiles superficiales, como el hielo, en los polos de Mercurio.
Principales métodos:
- Utilizó la antena de 70 metros de Goldstone para transmitir y el Very Large Array (26 antenas) para recibir señales de radar.
- Realizó experimentos de mapeo por radar a una longitud de onda de 3,5 centímetros el 8 y 23 de agosto de 1991.
- Se analizaron las características de eco del radar, incluida la relación de polarización circular (pt), para inferir las propiedades de la superficie.
Principales resultados:
- Mapeó con éxito una porción significativa de la superficie de Mercurio, incluidas las áreas más allá del polo norte.
- Identificó una región altamente reflectante en el polo norte de Mercurio.
- Se observaron relaciones de polarización circular excepcionalmente altas (pt) que oscilan entre 1,0 y 1,4 en la región polar, valores atípicos para los planetas terrestres.
Conclusiones:
- La alta relación de polarización circular observada sugiere fuertemente la presencia de hielo superficial en el polo norte de Mercurio.
- Estos hallazgos son comparables a las firmas de radar de las regiones heladas de Marte y los satélites de los planetas exteriores.
- Este estudio proporciona la primera evidencia inequívoca de radar para el hielo polar en Mercurio.
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