Earthlike Mars? |
Earthlike Mars? |
Apr 1 2009, 02:28 AM
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#1
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Member Group: Members Posts: 233 Joined: 21-April 05 Member No.: 328 |
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. |
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Apr 18 2009, 12:26 PM
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#2
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Member Group: Members Posts: 402 Joined: 5-January 07 From: Manchester England Member No.: 1563 |
Reading this paper, which i'm sure most people here already have, the thought has occured to me that occasional exceptional events , like small meteorite impacts , could bring preserved ice to the surface in areas where it would not ordinarily be stable, and that this ice might in a smallest of ways melt (short lived thin films on rocks in the debris field etc). Over bilions of years, could events like this account for some of the chemical evidence we see of liquid water on mars? That could have some bearing on theories like an ancient northern ocean.
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Apr 18 2009, 06:41 PM
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#3
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Senior Member Group: Members Posts: 2173 Joined: 28-December 04 From: Florida, USA Member No.: 132 |
...this ice might in a smallest of ways melt (short lived thin films on rocks in the debris field etc). Over billions of years, could events like this account for some of the chemical evidence we see of liquid water on mars? I wonder what the relative contributions to water-mediated changes in mineralogy are of: 1) Hot steam released by the initial explosive impact 2) Lingering sub-surface water/mud created by the impact 3) micro-films as part of an ice-rich environment equillibrium I wonder if the impacts add much to the changes caused already by near surface ice. There was evidence of water films at the Phoenix site as part of the normal equilibrium between ice, soil, and atmosphere. Why would the same films not exist in regions of near surface ice at lower latitudes even without the impacts? |
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Apr 19 2009, 09:52 AM
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#4
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Member Group: Members Posts: 402 Joined: 5-January 07 From: Manchester England Member No.: 1563 |
Isn't the phoenix data relating to thin films of water kind of ambiguous? There were some things, like soil stickiness, that could be evidence for thin water films, but the one sensor that would have given an unambiguous answer, the TECP, told us the soil was bizarrely dry considering it was sitting on a slab of ice and the humidity in the air above could reach 100%.
I think that the effect small ice exposing impacts would have on Martian soil and rock would depend on how frequent they are. Ice exposed on the surface at low latitudes will be more active than ice sequestered a meter or so below. If small impacts are frequent then they might up the overall rate of water activity at the surface. -------------------- |
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Apr 19 2009, 12:34 PM
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#5
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Member Group: Members Posts: 236 Joined: 5-June 08 From: Udon Thani Member No.: 4185 |
Isn't the phoenix data relating to thin films of water kind of ambiguous? I'm an amateur in this, but I still think those TECP readings are among the weirdest data Phoenix has been throwing at us, and with all the talk about water films on the lander etc I haven't seen any theorie which seems to explain those TECP readings. There is still a lot we don't know. Getting back to the 'warm and wet Mars', I'm still wondering whether we have any data which absolutely requires a long period with large liquid 'oceans' on Mars, also given the fact that it now looks like mineral deposits can also be formed inside ice fields. I can imagine there might be short 'floodwaves' and such due to vulcanic activity or large impacts on (surface or sub-surface) icefields but it's still a big step from there to an 'earthlike mars'. |
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