> On Sat, Mar 27, 2004 at 08:56:53PM +0900, Michael Turner wrote: > > > > Maybe elsewhere, but not on Mars. No sustained presence of liquid CO2 on > > > planetary surface, sorry. > > > > I am deeply touched by your faith (oh, I mean "absence of data"), Eugene. > > ;-) > > Yeah, and phase diagrams are one of my Ten Commandments.
And exactly what in your Ten Commandments makes Hoffman's hypothesis so unlikely? It seems to me you only have to assume that Mars, like the Earth, has evolved, and partly through collisions. Events that change atmospheric composition, temperature, pressure, possible vulcanism. > Where's all the carbonate, though? Don't see any models incommensurable with > a few mbar CO2 atmosphere. Did you read nothing else on that site? Lack of carbonates were one of the things that got Hoffman going in the first place. http://www.earthsci.unimelb.edu.au/mars/Paradox_Carb.html > Oh, it's very brief? Brief enough to create sediments, but lacking carbonate > right? Curious and curiouser. Enlighten us as to why. You're getting pretty elliptical here, Eugene. Specifically, I don't know why liquid CO2 flows would cause carbonates to form. Presumably, you're the chemist. (I sure know I'm not.) > It is a possibility, but it is a very, very distant possibility. Given the > demostrated presence of water, I'm going with Occam's razor... Given the much greater evidence of CO2 - i.e., the atmosphere, and one of the poles - I don't feel I have to "multiply" any causes without necessity in order to say: I don't know, and neither do you. We can now add (trace) evidence of water chemistry to our understanding of Mars. How this detracts from any hypothesis about a major shaping role for CO2 escapes me. Maybe I missed something in my science education, but that seems the more scientific attitude. Nobody has proved to me that CO2 can't have been liquid and flowing on the surface of Mars. Nobody has proved to me that evidence for liquid flows must be for water flows only. And how one arrives at an assessment of probability here (apart from nose-counting in the scientific community, a community thirsting for public funds) is also beyond me. -michael turner [EMAIL PROTECTED] == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
