Enceladus thoughts and more
Just giving everyone a heads up: I will be out of town starting tonight and will be in Flagstaff for a Titan Surfaces Meeting until Tuesday evening. While I am at it, yes Dad, I got the package. Thanks for the cookies! Anyways, my connection to the internet maybe spotty so don't expect too many updates here over the next couple of days.
On to Enceladus. This little moon continues to amaze. The views of this moon's south polar region were spectacular, including one very high resolution shot taken from a distance of only a few hundred km. Immediately one thinks of Europa, but one has to be careful comparing two very differently sized worlds. I can't count out the possibility of a liquid ocean, but the small size of Enceladus and the prevalence of cratered terrain makes me think that is not what we are see here. I think a more apt analogy is Miranda, with its own dichonomy between concentric ridged corona and heavily cratered terrain. In the case of Miranda, it is thought that upwellings of warm ice produced the coronae. A similar formation mechanism could be invisioned for Enceladus.
On to Enceladus. This little moon continues to amaze. The views of this moon's south polar region were spectacular, including one very high resolution shot taken from a distance of only a few hundred km. Immediately one thinks of Europa, but one has to be careful comparing two very differently sized worlds. I can't count out the possibility of a liquid ocean, but the small size of Enceladus and the prevalence of cratered terrain makes me think that is not what we are see here. I think a more apt analogy is Miranda, with its own dichonomy between concentric ridged corona and heavily cratered terrain. In the case of Miranda, it is thought that upwellings of warm ice produced the coronae. A similar formation mechanism could be invisioned for Enceladus.
posted by Jason Perry at 3:18 PM
4 Comments:
Jason, do you know of any internet references on Mirandan geology that are above press-release level stuff? There doesn't seem to be any real online material.
There is a good article on Miranda a few months back in the "Planetary Report" put out by The Planetary Society. The author is Bob Pappalardo.
What about free resources?
I've supersized my name for today. Sounds more like a B-movie monster than a boring ol' thermal emission spectrometer on Mars.
My comment is to mainly get the point out that just because 50% of the surface has a resemblance to Europa, doesn't mean you can invoke an ocean hypothesis, when there are SO MANY differences between Europa and Enceladus. First, the other 50% looks nothing like Europa, being heavily cratered. Second, the difference in size between Enceladus and Europa is enormous. You just can geophysically make a one for one comparison. I certainly agree with Bruce, episodic tidal heating that allows for localized resurfacing before it falls out of resonance is certainly reasonable, IMHO, but I don't know of any models have been done to examine its feasibility.
So my comparison to Miranda had more to do with that it a more reasonable analog for Enceladus than Europa, but as he points out, even that has problems.
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