Natural Habitats on Moon/Mars

[silylene old]

<i>Why do you think that Mars, which has much evidence for massive flows of surface water (flood plains, river networks), would not also have caves carved out by subsurface water flow? </i><br /><br />Usually on Earth, nearly all caves carved out by subsurface water flow are carved out of limestone, or some other carbonate mineral. There is no good evidence of largescale carbonate mineral layers on Mars.<br /><br />Caves can form in other minerals, for example in salt domes (karstification), but this is more unusual.<br />http://www.wordiq.com/definition/Cave <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[centsworth_II]

True, large caves on Earth have been formed by dissolution of limestone by carbonic (or sulfuric) acid. But why are you so sure that no similar process has occured on Mars? Opportunity has found sedimentary rocks composed largely of magnesium sulfate. The layers explored by Opportunity may be part a formation that is possibly hundreds of meters thick. The formation itself was formed in water and may have periodically been saturated and dried out. I don't think it takes much to dissolve sulfates and there is the possibility that sulfuric acid may have been present in the water. Are you really so sure that no such cave formation process could have taken place on Mars? <div class="Discussion_UserSignature"> </div>

 

[silylene old]

centsworth: I said "usually" in my post, speaking of terran caves.<br /><br />You bring up an excellent point that caves carved from hydrated MgSO4 strata are possible, perhaps even likely in some areas. Some hydrated MgSO4 salts are quite water soluble, while others are less soluble. Interestingly, how well they are hydrated is a subject of some very current debate. Anyways, water erosion of MgSo4 strata does give a good explanation of my pet theory, below.<br /><br />I long ago first speculated here that the interesting "trenches" we encountered (e.g. Anatolia) criss-crossing Meridani might be collapsed drainage tubes (In other words, small collapsed caves), or some type of small filled-in wadis, although most people on this forum said they thought they were shrinkage cracks. I am surprised so little attention has been paid to them. I would like to see a much more detailed examination to determine if they were originally a subsurface drainage system, or filled in wadis, or shrinkage cracks (and I would really hope that we investigate the prominent crack which leads into the northeast side of Endurance!). I was so disappointed each time when Opportunity rushed cavalierly over and past each linear depression feature on its trek to Endurance. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[silylene old]

<i>I suppose ice caves could exist on Mars, in the polar ice caps.....but it doesn't seem like a "natural habitat" to me, it's just too cold, and ice caves are ephemeral.....not a good place for life to develop. </i><br /><br />Actually extremophile bacteria and a tiny, multi-celled animal called a tardigrade do thrive in some deep ice-caves in Greenland. http://www.findarticles.com/p/articles/mi_m1590/is_9_58/ai_83451290 <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[centsworth_II]

<font color="yellow">"I would really hope that we investigate the prominent crack which leads into the northeast side of Endurance!"</font><br /><br />I think I could see some of the same 'cracks' on the North side of Victoria crater in the high resolution images recently posted of that crater. If Opportunity has the good fortune to cross the 'etched' terrain and reach Victoria, there may be another opportunity to examine this type of feature. <br /><br />P.S. I rarely have any problem with your posts. My reaction was to the omniscient certitude dislayed by crazyeddie. <div class="Discussion_UserSignature"> </div>

 

[chew_on_this]

Don't fall off your soapbox ranting like a loonie about something you can't prove. Funny stuff.

 

[centsworth_II]

<font color="yellow">"Please point out exactly where I have implied that I am somehow the final word on this subject?"</font><br />An over reaction on my part to your use of the word "probable": "...probable that the terrestrial planets only had caves created by volcanic processes, or talus caves." <br /><br />You keep going back to the lack of limestone (calcium carbonate) on Mars to support your belief in the lack of limestone caves. I'm asking about the possibility of caves in beds of <b>sulfates</b>. Do you not see this as a possibility? Dare I say... probability?<br /> <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<font color="yellow">"...life on Mars is about as IMprobable as life on any moon of Jupiter."</font><br />I bet you're the kind of person that buys a lottery ticket and then, instead of dreaming of how great it would be to win, bemoans the fact that you are certain to loose.<img src="/images/icons/smile.gif" /><br /> <div class="Discussion_UserSignature"> </div>

 

[silylene old]

<i>The climate in Greenland and the Antarctic are virtual ecological paradises compared to Mars, with no real atmosphere, no real water and no history of life or anything like it. </i><br /><br />stevehw33: I agree with you. I was simply pointing out that <i>if</i> there were life on Mars (which I think is highly unlikely) which existed in a cave, I think that life would be found in an ice cave, not in a limestone cave, or a salt dome cave, or a MgSO4 cave.<br /><br />I do think that MgSO4 caves are within the realm of possibility. I doubt life exists in them.<br /><br />But I also find discussing this hypothetical situation of Martian life to be interesting. And I think discussing the possibilities of Martian caves and their various methods of formation interesting. Let me enjoy my fantasies! <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[paleo]

stevehw33,<br /><br /> As a geologist and paleontologist I must give you praise for the sane postings on this thread.

 

[paleo]

centsworth: "I bet you're the kind of person that buys a lottery ticket and then, instead of dreaming of how great it would be to win, bemoans the fact that you are certain to loose"<br /><br /> Science has nothing to do with optimism. It is to do with evidence and reality. 'Wishing' or 'Dreaming' that there may be life in these 'caves' (?) on Mars does not make it any more or any less real. There are not leprechauns and fairies and elves because we wish for them to exist ...or Santa Claus. Physics and chemistry just 'is' and exists independent of man's dreams or desires.<br /><br /> Sure I 'wish' there was life on Mars but as a scientist I don't think there is. I 'hope' I'm wrong but that hope has no influence on the presence or absence of evidence of life.<br /><br /> When one studies the reality of the universe with a scientific rigour then one soon discovers that reality is much more fantastic than the imaginary universe many wish for.

 

[centsworth_II]

<font color="yellow">"Let me enjoy my fantasies!"</font><br /><br />Mars already has the largest canyon in the solar system and the largest volcano in the solar system. Maybe it also has the (yet to be discovered) largest cave in the solar system. <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

"stevehw33,<br />I must give you praise for the sane postings on this thread." -- paleo<br /><br /><br />"They want what they want, what they want. So dam the facts and all reason and the sciences. <br />And they will never learn, either., I'd sooner answer a Witness at my front door as engage with those loonies." -- stevehw33<br /><br /><br />Ah, yes, the voice of reason.<br /><br /><br /><br /> <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<font color="yellow">"Sure I 'wish' there was life on Mars but... I don't think there is. I 'hope' I'm wrong.... <br />When one studies the reality of the universe with a scientific rigour then one soon discovers that reality is much more fantastic than the imaginary universe many wish for." -- paleo</font><br /><br />I could have written these words myself. In fact I have written some variation of them on several occasions when addressing the fantasies of those who think they see signs of past civilizations, or even fossils, in Mars images. <br /><br />But given the mystery of the sudden appearence of life on Earth -- virtually as soon as liquid water was able to exist -- I don't see it as unscientific to imagine the same might have happened on Mars. And given the success with which life has overcome almost every concievable obstacle to permeate virtually every environment on Earth, I don't see it as unscientific to imagine that the same may have happened on Mars. <br /><br />If life ever existed on Mars, I don't expect it ever got past a stage similar to bacteria on Earth. I hope we are spending billions of dollars to send science instruments to Mars (in the years to come) that can detect the presence of life (past or present) because <b>scientists</b> think it is a worthwhile effort. You yourself say you hope you're wrong in your belief that there is (and never was?) life on Mars. So you acknowlege the need to investigate the possibility. Otherwise how would you find out if you were wrong? So you <b>do</b> see that the investigation of possible life on Mars can be a scientific endevor. <div class="Discussion_UserSignature"> </div>

 

[paleo]

Absolutely true. There is, however, a scientific process through which we decide where to put our resources. I don't go looking for paleozoic invertebrate fossils in younger rock, especially if it's not sedimentary rock...etc.<br /><br /> Mars? I don't think there was ever any life even though I think there's life on a quadrillion planets in the Universe. a quadrillion is not a lot...it's still a small fraction (a millionth?) of the total number of planets.<br /><br /> You mention that the origin life is a mystery. That is true. but that mystery has a chemical basis and is scientific. We just don't know what it is. We can't (yet) replicate it in a lab. I think the specifics are very precise for life to begin. There is a necessary temperature, chemical mixture, pressure, etc. Then new variables that supplant these variables to continue the life process. A whole basket of precise variables. I don't think Mars was ever like the Earth and created all those variables coming together at the same time. The needed exact temperature with the exact molecules with the exact pressure and exact radiation and exact cooling and exact warming and exact...etc. If the origin of life was more plastic and open to a wider range of variables then I think we would know how to replicate it.<br /><br /> Should we continue to search for life on Mars. Sure. Why not? There's no downside but we have to do it within realistic expectations. I'm all gung ho to go for it but that doesn't mean fudging the science with a bunch of so-called 'facts' that have no evidence.

 

[marcel_leonard]

<font color="yellow">I suppose ice caves could exist on Mars, in the polar ice caps.....but it doesn't seem like a "natural habitat" to me, it's just too cold, and ice caves are ephemeral.....not a good place for life to develop. </font><br /><br />Yes...if you are referring to indiginous lifeforms, but as far as colonizing the moon/mars they make very good places to continued developement of our way of life... <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>

 

[chew_on_this]

Calling someone a loonie for persuing the possibility of life on Mars or the moons of Jupiter is not a reasonable action to say the least.

 

[paleo]

??. I didn't call anybody a loonie. I said I was gung ho to continue the search. Not my post.

 

[chew_on_this]

stevehw33 wrote :<br />"Like most of Mars, past present and future. The life on Mars crowd simply cannot get it thru their unrealistic and unscientific heads that life on Mars is about as IMprobable as life on any moon of Jupiter. <br /><br />They want what they want, what they want. So dam the facts and all reason and the sciences. <br /><br />And they will never learn, either., I'd sooner answer a Witness at my front door as engage with those loonies. <br /><br /> You wrote: <br />"stevehw33, As a geologist and paleontologist I must give you praise for the sane postings on this thread."<br /><br />Comprende'?<br />

 

[silylene old]

I would be surprised not to find ice caverns, given some of the photos of the icecaps that I have seen. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[nexium]

Keep in mind that we have only explored a millionth part of the surface of Mars, rarely even a centimeter below the surface and even what has been explored is rather superficially. Why have we concluded no limestone? Why have we concluded no tetonics? Why not volcanoes errupting a few decades ago, and far into the past? Why do we think impactors big enough to distroy caves 1000 of miles away with the shock waves, when none have hit Earth that big the last 64 million years? Why do we think we know about small caves (isn't 8 cubic meters big enough for a habitat 1 meter wide, 2 meters tall and 4 meters long) 20 miles below the surface of Earth, Mars or any other body? Would you regard a billion caves averaging 8 cubic meters as essentually no caves? Mars has about ten million square miles. If caves occur to 100 miles below the surface, that is one billion caves at an average of one cave per cubic mile. Neil

 

[marcel_leonard]

<font color="yellow">Keep in mind that we have only explored a millionth part of the surface of Mars, rarely even a centimeter below the surface and even what has been explored is rather superficially. Why have we concluded no limestone? Why have we concluded no tetonics? Why not volcanoes errupting a few decades ago, and far into the past? Why do we think impactors big enough to distroy caves 1000 of miles away with the shock waves, when none have hit Earth that big the last 64 million years? Why do we think we know about small caves (isn't 8 cubic meters big enough for a habitat 1 meter wide, 2 meters tall and 4 meters long) 20 miles below the surface of Earth, Mars or any other body? Would you regard a billion caves averaging 8 cubic meters as essentually no caves? Mars has about ten million square miles. If caves occur to 100 miles below the surface, that is one billion caves at an average of one cave per cubic mile.</font><br /><br />There is little doubt that the same geology that formed caves here on Earth; also formed caves on all of the terrestrial planets. The real question is do these caves provide a natural habitat for off-world bases, and early outpost for colonization of the Moon/Mars? <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>

 

[centsworth_II]

<font color="yellow">"I think the specifics are very precise for life to begin.... I don't think Mars was ever like the Earth and created all those variables coming together at the same time." -- paleo</font><br /><br />It is possible that the origin of life requires very specific conditions that happened to occur on Earth at just the time that liquid water began its permanent presence. On the other hand, it could be that the type of chemical organization that eventually leads to life is engrained in the laws of nature, down to the quantum behavior of elementary particles, atoms, and molecules. And the only necessary conditions (along with the presence of a variety of elements) are those that allow for the presence of liquid water.<br /><br />The presence of liquid water on large areas of Mars for just 100 million years may have been sufficent for this natural tendancy of nature to organize matter into life to take place.<br /><br /><br /><br /><font color="yellow">"If the origin of life was more plastic and open to a wider range of variables then I think we would know how to replicate it." -- paleo</font><br /><br />What is easy for nature is not necessarily easy for our scientists. I suspect that this is because nature works on a quantum level that we have not mastered. The problem-solving power that our scientists dream of having at their disposal once they succeed in building quantum computers is already (and has always been) at nature's disposal. <br /><br />Before you think I've gone off the deep end, let me remind you that many books have been written by respected scientists which describe how quantum behavior of nature's fundamental particles allows for the existence of things we still do not understand: behaviour of light, human consciousness, and... the origin of life. On the last subject, I recommend "Quantum Evolution" by Johnjoe McFadden.<br /><br />I don't mean to sound mysterious, but at its most fundamental level, nature <b>is</b> myste <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<i>"...ancient caves [on Mars] would likely not survive that long because meteoric bombardment over the eons would create shock waves that would eventually cause large caverns to collapse." -- crazyeddie</i><br /><br />Mars' caves would be somewhat more resitant to collapse than those on Earth due to the reduced force of gravity. My earlier comment about Mars having the largest cave in the solar system was made in jest, but because of the lower gravity, if a cave formation process existed, it could perhaps build larger stable caves on Mars than on Earth. <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<i>"The largest cave on Earth...was created by the percolation of precipitated water, mildly acidified by <font color="yellow">carbonic acid</font>.. through a layer of <font color="yellow">limestone</font>...Until and unless some similar process can be identified to have occurred on Mars in the present or the past, with some explainable mechanism by which minerals are degraded and removed in order to create a chamber, it is unreasonable to suppose that Mars has caves larger than any on Earth." -- crazyeddie</i><br /><br /><br />Replace the highlighted words above with sulfuric acid and sulfates. Then you have a cave formation senerio on Mars similar to the one you describe for Earth. No need for tectonics to raise and lower beds of sulfates for cave formation to take place. The level of Mars' acid oceans raising and lowering over thousands or millions of years gives the same result.<br /><br />As for a process of dissolving and removing material, the Mars rover Opportunity has already provided photographic evidence that such a process existed. Below are microscopic images taken of sulfate layers from which material has been dissolved and removed. Of course the voids <b>could</b> be bubbles formed by some outgassing process, but I think the dissolution and removal of material is the more likely process. Granted, the images show the results of this process at a very small scale, but if it exists at this scale, it is only a matter of time for the scale to rise to that of caves. If the process existed on mars. The only question is are there sulfate layers thick enough and were they exposed to rising and lowering (or running) acid water long enough to form caves. <br /><br /> <div class="Discussion_UserSignature"> </div>