Earthlike Mars? Options

[glennwsmith]

All, I know this isn't the right place for this post, but I've looked around and can't find an appropriate, current UMSF forum (Doug, perhaps you could give me some guidance on establishing such) -- so here goes: I think a [the] new paradigm for Martian geology is rapidly coalescing, namely, that Mars is very much like the Earth in terms of the preponderance of water -- except that it is all frozen, and covered under a thin layer of dust/regolith! See, for example, this article:

http://www.skyandtelescope.com/news/41995902.html

Hence the "seepages" found in crater walls; hence the evidence of catastophic flooding -- the result of volcanism melting huge pockets of ice. And I am going to add my own wrinkle (probably not original): that the differentiation of Mars into a rougher southern hemisphere and smoother northern hemsphere represents something like Earth's Pangea stage, ie, the northern hemisphere is a vast frozen sea covered with a thin layer of ice.

[glennwsmith]

The possibility that there is a frozen Oceanus Borealis beneath the dust of the northern plains has implications far beyond Mars, of course. If I may be allowed to speak in an enthusiastic vein for a moment, consider that Mars is only the second planet that we have been able to "sample". Finding large quantities of water there would thus, in a sense, double the amount of water likely to be extant among the universe's population of rocky planets.

The verification of an Oceanus Borealis also increases the liklihood that we will find significant quantites of water on our own moon; or -- to put this in negative terms -- if Mars is cold and dry, this does not bode well for the success of the current LCROSS mission to the moon.

By the way, I'm sure most of you are aware of yet another recent paper pointing to the presence, at least in the past, of a significant body of water on Mars; the link follows:

http://www.colorado.edu/news/r/7e9c22ec0cd...4ed2e29f16.html

[tim53]

By the way, I'm sure most of you are aware of yet another recent paper pointing to the presence, at least in the past, of a significant body of water on Mars; the link follows:

http://www.colorado.edu/news/r/7e9c22ec0cd...4ed2e29f16.html

I looked at this paper after I was notified of the press release last week. Their "shoreline" is a fault scarp in alluvium, similar to this example from Nevada. I worked there 30 years ago. It can be difficult to distinguish shorelines from fault scarps across the alluvial fans in the Great Basin because they often are directly associated with one another. This example is "easy" because there's a graben in front of the main fault, but there isn't always one. In this valley ("Dry Valley" I think it was called, though the map software doesn't show the name) west of Caliente, Nevada, the paleolake was rather small and didn't rise to the elevation of the fault scarp.

Fortunately, of course, we could drive up to and walk on the feature to help us determine what it was.

In the martian example, we can't do that (not for a while, at least). So I'm afraid that in my view at least, the paper fails to provide the extraordinary proof that the claim "This is the first unambiguous evidence of shorelines on the surface of Mars" represents. ...in addition to it simply being an untrue statement.

-Tim

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