Re: Standing Body of Water Left Its Mark in Mars Rocks
On Sun, Mar 28, 2004 at 07:55:48PM -0800, James McEnanly wrote: > > >From what I've been reading on Supercritical Co2 > http://p2library.nfesc.navy.mil/P2_Opportunity_Handbook/5_17.html, > it is an excellent organic solvent, but I don't know > how well it would do on the types of deposits the > rovers have been finding I have been abstaining from that thread, since being off-topic for Europa (yeah, as a matter of fact I'm a chemist, albeit not a geologist/geochemist). Liquid CO2 is one thing, supercritical CO2 is another beast entirely. Look at the phase diagram: http://www.che.gatech.edu/ssc/eckert/prospectus/ngso3c/sld012.htm -- Eugen* Leitl http://leitl.org";>leitl __ ICBM: 48.07078, 11.61144http://www.leitl.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE http://moleculardevices.org http://nanomachines.net pgp0.pgp Description: PGP signature
Re: Standing Body of Water Left Its Mark in Mars Rocks
>From what I've been reading on Supercritical Co2 http://p2library.nfesc.navy.mil/P2_Opportunity_Handbook/5_17.html, it is an excellent organic solvent, but I don't know how well it would do on the types of deposits the rovers have been finding --- Michael Turner <[EMAIL PROTECTED]> wrote: > > Gary, among the staunch Martian water advocates, > you've made what I think is > the best contribution to the debate so far. This > contribution is the phrase > "satisfactorily uncomfortable." That's got my vote > for Oxymoron of the > Month. And it's quite a bit funnier than Eugene > Leitl's non sequitur, > "Faith = absence of data." > > From what I can see, all we have is this: > > (1) there is solid evidence of water chemistry > (2) there is persuasive evidence of liquid movement > on the surface > > Where is the evidence that the water chemistry stems > from the same liquid > that moved on the surface, meaning that this liquid > was certainly almost > entirely water? > > For your sake, I interpret the following as a > Freudian slip, but as a wry > joke: > > > BTW, us scientists do solicit funding, but most > try to not let the > > facts get in the way. > > As for this: > > > you and others on this list (Eugen, Jim, et al.) > have made it obvious > > [liquid CO2] too much of a long shot. > > ... well, "too much of long shot" is everyday > English for "neglibly > probable." Certain pundits' rantings > notwithstanding, probability is a > measure of belief. "Frequentist" arguments are > still fundamentally this > Bayesian measure, since probability and statistics > have been intelligently > co-designed for agreement at the limit of > statistical observation. Do we > have enough data for a "frequentist" probability > assessment about liquid CO2 > flows on Mars? I haven't seen it. So we're back to > probability as a > measure of belief. And that takes us back to > theory, still far from > complete. > > From dozens of casual observations, it's pretty easy > to build a frequentist > case for the intuitively obvious proposition > "heavier things fall faster." > Ancient Greek ballisticians (a smarter bunch than > people realized until > recently) must certainly have known that this wasn't > true, but probably > shrugged off the popular misconception, because > their jobs were safe as long > as there were imperious Romans, bloodthirsty > pirates, and other Greeks > willing to go to war with the ballisticians' > city-states. Just as people in > Columbus' time who knew better could shrug off the > superstition that the > earth was flat. Any ship's captain who made an > issue of it wasn't going to > get a good navigator, and that ship would be > increasingly unlikely to make > it back to port. Evolution in action. > > But we're dealing with evidence of water on Mars > here, where it's extremely > expensive and time-consuming to make even a handful > of the required > observations, and in a context whose political > economy is a very different > kettle of fish than the one from which Greek > ballisticians and 15th century > navigators ladled out such nourishing broth. Gary, > can you tell me for sure > that you know that there have been enough of the > right kinds of observations > to make an assessment of liquid CO2 flows on Mars as > being *neglibly* > probable? Until I see evidence of such > observations, I would tend to go > with (literal) weight of evidence: there is a huge > amount of CO2 on Mars, > but apart from the polar caps, the only evidence of > water on other parts of > the surface has been derived from subtle chemical > experiments by probes that > can cover only a small amount of that surface. > > -michael turner > [EMAIL PROTECTED] > > > - Original Message - > From: "Gary McMurtry" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Sunday, March 28, 2004 3:32 AM > Subject: Re: Standing Body of Water Left Its Mark in > Mars Rocks > > > > > > Michael, > > > > First, may I suggest a better question to bat > about may be "if there > > is now mounting evidence for abundant liquid water > once on Mars, > > where did it go and why?". I appreciate your > pursuit of a competing > > hypothesis for liquid CO2, because I think in > trying to suggest it, > > you and others on this list (Eugen, Jim, et al.) > have made it obvious > > it's too much of a long shot. > > > > BTW, us scientists do solicit funding, but most > try to not let the > > facts get in the way. Most of our funding awards > are peer reviewed, > > which although an imperfect and increasingly > overtaxed process, still > > functions to weed out the crud. As you probably > know, unlike > > religion, science is self-correcting and evolves > through time. We > > are satisfactorily uncomfortable with our present > knowledge state. > > > > Gary > > > > >--- Michael Turner <[EMAIL PROTECTED]> wrote: > > > > > >> > > >> So I'm still holding out for a possible CO2 > > >> sea/ocean/lake as an explanation > > >> for fe
(no subject)
unsubscribe europa
Back on-topic
OK Jeff, Here's a tie-in 'on topic' remark about Europa and Mars. Both apparently have magnesium sulfate (MgSO4) on their surface. The suggested common origin of these salt deposits is precipitation from a salty body of water. Fraser Fanale et al. showed in a JGR paper (ca. 2000) that when you leach a stony meteorite with warm distilled water, out comes magnesium sulfate. This finding has important implications for past and present hydrothermal systems, depending on how representative the samples in question are (on Mars, a few rock outcrops, on Europa, the entire surface of the moon). Since we know Mars has volcanoes (just a few, the the biggest known) the finding of magnesium sulfate is obviously not controlling a presence/absence of volcanism and associated hydrothermal activity there (but maybe it is on the latter, on second thought). However, on Europa, if there is an ocean in contact with a seafloor hosting volcanism and associated hydrothermal activity (highly likely underwater), abundant magnesium sulfate signals a problem. On Earth, both magnesium and sulfate are consumed by rock alteration, and consequently are not the dominant ions in ocean water (any more). Logic then suggests either: (1) there is and has been no abundant seafloor hydrothermal activity on Europa (with life implications there); or (2) the Europa starting conditions or history are so unlike Earth that you can indeed have both a MgSO4 ocean and abundant seafloor hydrothermal activity. It seems the important point I keep missing in Michael's posts on Hoffman and liquid CO2 is that it is indistinguishable in physical effects from liquid water. I agree, but it is very different in chemical effects, with the supporting data on the latter contingent upon how representative the salty rocks are of larger liquid bodies on Mars. This will continue to loom until we get further data. Comparative planetology is what the entire global space programs are about, n'cest pas? Gary A gentle reminder that the purpose of this mailing list is the discussion of Europa, not Mars. There are far more appropriate fora for the discussion of Mars-related topics than this mailing list. The relevance of Mars exploration with respect to future missions to Europa would be on topic, but outside of that context is not. Your anticipated cooperation is greatly appreciated, and will make it easier for me to continue to maintain this mailing list. Sincerely, Jeff Foust list administrator [EMAIL PROTECTED] == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/ == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
Articles on Europa in Astrobiology Magazine Vol. 3, No. 4 2003
A whole special section devoted to our favorite moon may be found here: http://zerlina.ingentaselect.com/vl=1554396/cl=48/nw=1/rpsv/cw/mal/15311074/v3n4/contp1-1.htm Larry
Re: Standing Body of Water Left Its Mark in Mars Rocks
--- Michael Turner <[EMAIL PROTECTED]> wrote: > In any case, the ghost of Lowell could still use > some exorcism. Arthur C. > Clarke, less than a year ago, said over the wire at > some conference that he > was sure he saw something in recent surface images, > evidence of life gosh > darn it. Clarke's a very intelligent and > imaginative guy, and a good > writer. But please. And let us not forget that (on-topic alert!) Clarke was also contending a while back that one of the big long cracks in Europa was too straight and long, and was therefore most likely to have been created by intelligent life. And given that "Mysterious World" show he used to host, it would really seem to me that he falls on the more credulous side of the spectrum. Maybe he's just being hopeful in his twilight years. I wouldn't begrudge him that, he's earned it... --Mark __ Do you Yahoo!? Yahoo! Finance Tax Center - File online. File on time. http://taxes.yahoo.com/filing.html == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
I just had to send this one - imagine a Berserker version of Icepick
EDITOR'S CHOICE: DEEP CUT It may sound like something out of bad sci-fi movie, but a chainsaw-wielding robotic submarine is roving under a Canadian lake for real. Its job is to cut down trees that were submerged decades ago after the valley was flooded by a hydroelectric dam. The three-tonne yellow submersible is called Sawfish and may soon be available for sale to other loggers - it is believed that there are some 200 million drowned trees around the world... MORE http://www.newscientist.com/news/news.jsp?id=ns4811TOP STORIES:Life on Mars - but 'we sent it'There is life on Mars, one NASA-funded microbiologist tells a conference - unfortunately it is just spaceship-borne contaminationhttp://www.newscientist.com/news/news.jsp?id=ns4812Earth's 'quasi-moon' is wayward asteroid The object actually orbits the Sun, but its corkscrew path means it appears to orbit Earth that from time to timehttp://www.newscientist.com/news/news.jsp?id=ns4814Early humans swapped bite for brainHumans may owe their big brains and sophisticated culture to a single genetic mutation that weakened our jaw muscles about 2.4 million years agohttp://www.newscientist.com/news/news.jsp?id=ns4817Beach rover uncovers Mars's ancient oceansThe landing site of the rover Opportunity was once the shore of a shallow and very salty sea, NASA scientists declarehttp://www.newscientist.com/news/news.jsp?id=ns4808
ADMIN: on-topic reminder
A gentle reminder that the purpose of this mailing list is the discussion of Europa, not Mars. There are far more appropriate fora for the discussion of Mars-related topics than this mailing list. The relevance of Mars exploration with respect to future missions to Europa would be on topic, but outside of that context is not. Your anticipated cooperation is greatly appreciated, and will make it easier for me to continue to maintain this mailing list. Sincerely, Jeff Foust list administrator [EMAIL PROTECTED] == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
Carbon dioxide landform on Mars
MARS GLOBAL SURVEYOR IMAGESMarch 18-24, 2004The following new images taken by the Mars Orbiter Camera (MOC) onthe Mars Global Surveyor spacecraft are now available:o Carbon Dioxide Landforms (Released 19 March 2004) http://jpl.convio.net/site/R?i=xdPqwJJBoiBO-3BCLCXxIg..
Re: Standing Body of Water Left Its Mark in Mars Rocks
Title: Re: Standing Body of Water Left Its Mark in Mars Rocks This is all very interesting, Gary, but please note that I've never argued that the current evidence for water chemistry is flawed. I have no trouble with the conclusions arrived at so far about water chemistry. And it's good to know that sediment can't form in CO2 (or that, if it does, it's not common knowledge how it could - I'm not sure what's been done in finding analogous processes, given how unlikely they might have seemed until now.) However, nothing you've said addresses my main question: how does any of this evidence for water chemistry preclude formation of larger-scale features on Mars through CO2 phase changes? Your ability to tell me what's in a high school chemistry refresher is evidence only that you have some time on your hands. The fact that you haven't addressed the above question (repeated here for what may be the third time, in a different form) tells me either that you haven't been reading (in which case, why reply?) or that you're evading the question. Hoffman's website carries the provocative banner of Mars Without Water. By this, he doesn't mean "Mars has no water." For one thing, the poles and the traces of water vapor in the atmosphere are established facts - if he were saying "Mars has no water", he'd be a total crank. Given, however, that he talks about small amounts of water and the role that these amounts might play in White Mars (necessarily almost negligible, given his thesis), you can't pin the crank label on him. At least, not on that basis. What he means is "Plausible Explanations for Apparent Martian Hydrology that Don't Require Hydrology." No points for diplomacy on his part, of course, but otherwise he's doing the right thing for garnering attention. And the more that he's misinterpreted by people who should know better, and who could think better, the more his provocation works for him. He gets to point out that certain people are engaged very superficial readings of his thesis, and only making themselves look lazy, incompetent, or both. If you want to make real progress against White Mars, you have to do it in terms at least as scientific as Hoffman himself - ideally, better. Off-the-point recitations from high school chemistry, as if they were some killer blow, amount to shooting yourself in the foot - precisely what he wants you to do. -michael turner [EMAIL PROTECTED] - Original Message - From: Gary McMurtry To: [EMAIL PROTECTED] Sent: Sunday, March 28, 2004 2:59 PM Subject: Re: Standing Body of Water Left Its Mark in Mars Rocks Michael, OK, since you asked, sit down and I will give you a mini-lecture on molecular chemistry. The evidence for water is the salts. I have it from a particular Mars planetary scientist (pers. comm. on Thursday) that the now-famous "blueberries" are mostly hematite (Fe3O4--its false color, folks), and that the matrix material that the "blueberries" rest upon and are incorporated within, has lots of magnesium sulfate (MgSO4) a.k.a. Epsom salt, in it. Water is a polar molecule with amazing solvent properties. It is polar because the two hydrogen atoms are mostly on one side, at about 105 degrees separation. That side therefore has a slightly positive charge. Conversely, the oxygen side of the molecule is slightly negative in charge. This is because the electrons in their clouds spend slightly more of their time on the oxygen side, and less upon the hydrogen-bonded sides. The polarity of water makes it able to pluck surface cations from rocks and, importantly, hold them in solution. This polarity causes water molecules to surround cations (and, flipping the molecule around, anions) and gives water other amazing properties (increased heat capacity, freezing and boiling point suppression), because it has structure. Carbon dioxide is not polar. Its molecular structure is a linear 0-C-0. Liquid CO2 cannot therefore do the feats listed above for liquid water, among them pluck and hold ionic salts in solution, to later precipitate upon evaporation in sediments and make salt-saturated rocks like those recently found on Mars. Gary Gary, among the staunch Martian water advocates, you've made what I think isthe best contribution to the debate so far. This contribution is the phrase"satisfactorily uncomfortable." That's got my vote for Oxymoron of theMonth. And it's quite a bit funnier than Eugene Leitl's non sequitur,"Faith = absence of data.">From what I can see, all we have is this: (1) there is solid evidence of water chemistry (2) there is persuasive evidence of liquid movement on the surfaceWhere is the evidence that the water chemistry stems from the same liquidthat moved on the surface, meaning that this liquid was certainly almostentirely
Fw: [DarlingsSpace] David Darling's Newsletter #20
- Original Message - From: daviddarling123 To: [EMAIL PROTECTED] Sent: Sunday, March 28, 2004 8:36 AM Subject: [DarlingsSpace] David Darling's Newsletter #20 DAVID DARLING'S NEWSLETTER-- Issue #20March 28, 2004e-mail: mailto:[EMAIL PROTECTED]website: http://www.daviddarling.info--NEWS ALERT: POSSIBLE DETECTION OF LIFE ON MARSThis is the first time I've sent out a news alert but there's been a discovery of such potential importance that I'd like you all to be aware of it without delay. The discovery is preliminary and it may turn out to be a false alarm. However, it's implications are so profound that I didn't want to wait for the next full newsletter to give you the heads-up.Briefly, it seems as if methane has been found in the Martian atmosphere. Separate teams from the NASA Goddard Space Flight Center and the European Space Agency have detected the presence of methane gas in small quantities. This is hugely significant because methane must be continually replenished, otherwise photochemical processes would remove it on a timescale of about 300 years. The likelihood is that the replenishment is done my methanogenic microbes in the Martian soil. In other words, this, as-yet-unpublished data, strongly points to the presence of living organisms on Mars.The story was broken in The Independent newspaper (London) yesterday and reads as follows:---A strong signal of life on Mars has been detected by scientists at the US National Aeronautics and Space Administration (Nasa) and the European Space Agency.Each group has independently discovered tantalising evidence of methane in the Martian atmosphere. Methane, a waste product of living organisms on Earth, could also be a by-product of alien microbes living under the surface of the Red Planet.The detection of methane has been the holy grail of scientists studying the Martian atmosphere, as its presence could provide unequivocal proof that there is life beyond Earth.Neither Nasa nor the European Space Agency (ESA) has publicly announced the findings, but specialists who have seen the data believe the discovery is genuine - although they are unsure what it means in terms of confirming the presence of life.The discovery comes weeks after Nasa and ESA announced new findings relating to the presence of huge bodies of water on Mars which could have supported life.The European effort is led by Vittorio Formisano, of the Institute of Physics and Interplanetary Science in Rome, who operates the methane-detecting spectrometer on board the Mars Express spacecraft orbiting the planet. "We can identify the presence of methane in the Martian atmosphere and we've been able to evaluate how much of it there would be," Professor Formisano said. "Globally, if I average all the data I have, I can find something of the order of 10 or 10.5 parts per billion. It's detectable, but only if I average a lot of data."Methane is destroyed by the intense ultraviolet radiation on Mars because the gas has a relatively short photochemical lifetime of about 300 years, so if it is present there must be something producing it continually, Professor Formisano said. "[Its presence] is significant and very important. If it is present you need a source," he added.The second group to detect signals of methane in the Martian atmosphere is led by Michael Mumma of Nasa's Goddard Space Flight Centre in Maryland, who used powerful spectroscopic telescopes based on Earth.This team is even believed to have detected variations in the concentrations of methane, with a peak coming from the ancient Martian seabed of Meridiani Planum, which is being explored by a Nasa rover.This could indicate a subterranean source of methane which is pumping out the gas, either due to some residual geological activity or because of the presence of living organisms producing it as a waste gas.Asked whether the continual production of methane is strong evidence of a biological origin of the gas, Dr Mumma said: "I think it is, myself personally."He added: "It's difficult to imagine that primordial methane [from geological activity] would continue outgassing for four billion years [the age of Mars]. This looks very intriguing."Both teams of scientists are now busy validating their results before their respective organisations are prepared to go public on the implications.(http://news.independent.co.uk/world/science_medical/story.jsp?story=505454)If any of you have further information, please contact me or post your comments on my forum.Best wishes,David Darling Yahoo! Groups Links<*> To visit your group on the web, go to: http://groups.yahoocom/group/DarlingsSpace/<*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED]<*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
