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Enceladus "Sea" Mystery Deepens
Smivs writes "The BBC reports that an ocean may not be the source of the jets emanating from Saturn's moon Enceladus. Controversial research questions the moon's promise as a target in the search for life beyond Earth. A chemical analysis of Enceladus, led by University of Colorado planetary scientist Nick Schneider, failed to detect sodium, an element scientists say should be present in any body of water that has been in contact with rock for billions of years. Spectral analysis with the Keck Telescope found no sodium in the plumes or in the vapor in orbit around the moon. At stake is whether Saturn's moon could support alien life and is thus a worthy target for a NASA exploratory mission to detect it. Such a mission to Enceladus is one of four currently under review for further development."
http://www.thunderbolts.info/tpod/2006/arch06/060313moonjets.htm
"A man cannot begin to learn that which he thinks he already knows." --Epictetus, 1st Century A.D.
Perhaps it is something that we have not tested and only assumed for a fact?
Although a lack of salt is a fine excuse to not send a mission here, the better reason is that these missions are a tremendous waste of taxpayer resources. While I am no free market capitalist, it is waste like this which give fire to those who say that government can't make financially sound decisions. Lets focus our space program on useful tasks such as orbital solar energy collection and leave the fruitless search for extraterrestrial life to the hobbiests.
Subject asks it all. Would it be possible for Enceladus to be pure ices with little or no rocks? It is a round moon, so it should be differentiated. Could that differentiation be layers of ices (say water Ice III below, leading up to softer ices including other volatiles) without rocks? Enceladus could still have an ocean, just one without rocks. This presents potential life-genesis issues (which generally require rock-chemistry) but presents no inherent conflict with the idea of it having an ocean.
Josh
gigantino.tv - Heavy but weighs nothing.
That's a pretty strong statement considering that the American public is being asked to pay for a mission to the planet to study these supposed cracks, and presumably to eventually study the supposed ocean beneath the ice. I think that most Americans would appreciate hearing more than just one viewpoint on how their money is being spent. One can be forgiven for getting the impression that most conventional astrophysicists would prefer to die trying to prove the Big Bang than have to take part in studying an alternative cosmology.
"A man cannot begin to learn that which he thinks he already knows." --Epictetus, 1st Century A.D.
Someone needs to look at this from a thermodynamic perspective. If there is in fact water on Saturn's moon, it must come from the surface. I am not sure why orbiting clouds of frozen water vapor (which i believe must have sublimated from the icy surface) are expected to contain Sodium. Thermodynamically speaking, species with low mass, and high activity (The light elements H, N, O, C, F) tend to undergo phase change before more heavy elements. These low density gases would exit into the moons atmosphere more readily than a sodium atom, even if the surface contained equal concentrations of all. (on wiki it says the atmosphere is Water, 4%Nitrogen, 3.2%CO2, and 1.7%CH4) makes sense so far, Also, i believe that if there was an ocean on this moon, the surface must be ice of near pure water. If water is going to freeze, it will do so first with minimal sodium. The sodium content in the ice will increase when the ocean concentration rises, eventually precipitating solid sodium compound when a saturation limit is reached. This only means that the outer shell of the moons frozen surface might be mostly clean ice I believe any sodium that could be detected in orbit must first diffuse to the surface through this concentration gradient. And then gain sufficient activation energy from the suns rays to enter the gas phase for an instant. I think these scientists could be looking for the wrong indicator. If we are searching for water, shouldn't we be searching for water? It is possible they have the right idea, but our instruments are not precise enough to measure such a small Sodium concentration. And i'm not sure the Seas of Saturn will follow our earthbound concepts of oceanography.