Evidencias de la existencia de agua en Enceladus/ Evidences of water existence in Enceladus

Planeando a 25 kilómetros de Enceladus, la nave espacial Cassini ha obtenido la evidencia adicional de que el interior de esta minúscula y helada luna de Saturno podría contener agua líquida. Hunter Waite, del Instituto de Investigación del Sudoeste en San Antonio (Texas, E.E.U.U.) y sus colegas han basado sus hallazgos en las observaciones cercanas hechas con el espectroméro de masas iónicas y neutras de la Cassini, que entre el 12 de marzo de 2008 y el 9 de octubre de 2008 muestreó los penachos de partículas heladas y vapor de agua que son emitidos desde dicha luna.

Uno de los hallazgos es que el penacho contiene amoníaco, que se disuelve fácilmente en agua y permite que el agua permanezca líquida a temperaturas más bajas de las que podrán ser posibles en la luna Enceladus. Otro hallazgo, es la probable detección de Argon-40, que podría haber llegado hasta el penacho transportado por las corrientes de agua dentro de Enceladus.

Los investigadores llevan especulando la posibilidad de existencia de agua líquida en el interior de Enceladus desde l año 2005, cuando la nave espacial Cassini descubrió un géiser de partículas de hielo y vapor que surgía de las grietas del polo sur de la luna. La posibilidad de agua líquida dentro de la luna, junto con la gran variedad de compuestos orgánicos encontrados en el penacho, sugiere que Enceladus pudo ahora o en el pasado reciente haber tenido la materia adecuada para mantener la vida.

Swooping within 25 kilometers of Enceladus, the Cassini spacecraft has obtained additional evidence that the interior of this tiny, icy moon of Saturn may contain liquid water. Hunter Waite of the Southwest Research Institute in San Antonio and his colleagues base their findings on close-up observations made with Cassini’s Ion and Neutral Mass Spectrometer, which on March 12, 2008 and October 9, 2008 tasted the plumes of icy particles and water vapor known to spew from the moon.

One finding is that the plume contains ammonia, which readily dissolves in water and acts to keep liquid water at lower temperatures than would otherwise be possible in the moon. The other finding is the probable detection of argon-40, which might have been transported to the plume by liquid water coursing through minerals inside Enceladus.

Researchers have speculated about the possibility of liquid water within Enceladus since 2005, when the Cassini spacecraft discovered a geyser of ice particles and vapor emanating from cracks in the moon’s south pole. The possibility of liquid water inside the moon, along with a variety of organic compounds found in the plume, suggest Enceladus may now or in the recent past have had the right stuff to support life.

Tomado de/Taken from Science News

Resumen de la publicación científica/ Abstract of the research paper
Waite, JH ,: Lunine, J I, McKinnon, W B, Glein, C , Mousis, O, Lewis, W S, Magee, B, Westlake, J, Nguyen, M, Young, D T, Brockwell, T, Teolis, B,
Ammonia, radiogenic argon, organics, and deuterium measured in the plume of Saturn's icy moon Enceladus, Jt. Assem. Suppl., Abstract.
Abstract
Observations made with the Cassini Ion and Neutral Mass Spectrometer (INMS) during two close flybys of Enceladus on 12 March and 9 October 2008 reveal the presence of ammonia, complex organics such as benzene, and deuterium in the gas plume as well as the probable presence of radiogenic argon. The INMS data provide compelling evidence for the existence -- today or in the recent past -- of liquid water in Enceladus' interior and support a hybrid model for the source of the plume, with contributions from both degassing volatile- charged ice (in the form of clathrate hydrates) and material that is or recently was in a reservoir of liquid water. The measurement of the ratio of deuterium to hydrogen is the first such measurement at an icy satellite and is consistent