Quote from: PlattsWater concentrations at the ppt level within the Moon provides strong evidence that the Moon is still outgassing water, and that such outgassed water is at least a partial source of the ice detected in polar craters. Indeed, it's likely that there is liquid water (and therefore life) within sublunarian aquifers! It is mildly amusing, at best, to read that in the not known to exist "sublunarian aquifers", we are "therefore" "likely" to find life.
Water concentrations at the ppt level within the Moon provides strong evidence that the Moon is still outgassing water, and that such outgassed water is at least a partial source of the ice detected in polar craters. Indeed, it's likely that there is liquid water (and therefore life) within sublunarian aquifers!
Considering the amount of material now known to have been exchanged between the inner planets during the LHB (when life was getting going on this planet) it's not a great stretch to ask whether viable living matter made it to the Moon. Hunting for (primarily chemical) fossils should be a major research goal when humans return to the moon in a serious fashion.
Are you referring to microbes or fumaroles??
How are these features created? Significant volcanism on the Moon largely stopped at least a couple of billion years ago. The Brown team thought that the combination of young age, low maturity and unusual morphology suggested a relatively uncommon pit-forming process. They proposed that the explosive release of volatile substances from the lunar interior would have disrupted the surface, created a chaotic mixture of rock and soil, exposed fresh surfaces (creating the immature spectral signature), and formed a collapse depression caused by the instantaneous removal of mass from below.Now we can see that the new Mercurian hollows have morphologies displaying spectral anomalies similar to the lunar collapse pits such as Ina. The new data suggest that Mercury contains significant volatile substances. These volatiles must be present at some depth, accumulated under high pressure until crustal failure ensues and a massive gas release results in an “eruption.” This explosive event leaves behind a chaotic, disrupted surface (“immature,” with fresh bedrock and deep regolith “newly” exposed to space).
[We present] the results of the analyses of microphotos of lunar regolith particles published earlier, which confirmed that lunar rock contains fossilized remnants of microbial organisms, that most probably had been functioning in hydrothermal springs.
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Quote from: Warren Platts on 07/29/2012 12:07 pm....Warren asks, "Who among you kind and gentle readers believe that the Martian meteorite contains compelling evidence of Martian life?" I answer, "Me!" Warren asks, "Then why do you discount similar evidence of Lunar life?I answer, "I don't discount evidence that Earth microbes might have survived on the Moon!" {snip}
....So, you're saying they probably are microbes, but that the Luna sample return mission just happened to grab a meteorite thrown up from the Earth 4 billion years ago.... Those are long odds. More importantly, if the rock came from Earth, they would be able to tell, just as we can distinguish meteorites that came from regular asteroids and meteors versus those that came from Mars or the Moon. Even if they didn't test for Earth isotopes, the idea that a single random grab from the Moon would actually grab an Earth rock stretches the imagination. Yes, people win the Powerball lottery every other day; yet I never seem to. Have you?More importantly, to deny that it is possible that life could be/have been on the Moon is to deny the presences of liquid water on the Moon. We can quibble about the exact nature of the thermal gradient, but that there are zones where the temperature and pressure regimes favor water in its liquid phase cannot be doubted. Therefore, you must be doubting the claim that there IS enough water within the Moon to fill in cracks in the rocks within the liquid favorable zone. Yet, you, Happy Martian, are the one who keeps repeating and reposting the same links as to how much water there is in the Moon! E.g., the orange soil has recently shown that Moon mantle and Earth mantle have comparable water concentrations. Something has to give. You must give up something. Which is it? EDIT: And what about the organic molecules detected by Chandrayaan? These are also consistent with the Lunar Life hypothesis:Universe Today: "Signs of Life of Life Detected on the Moon?" by Nancy Atkinson
Follow the water is supposed to be the rule in looking for life. I think it is a very good rule. If some forms of life managed to get to the Moon from Ceres, Mars, Earth, or somewhere else, then there is a good chance that if that life was buried deep enough in the Lunar environment where water in some form tends to be available, some of those immigrant forms of life would still be active today. Could life have evolved on the Moon and then caught a ride to Earth? Good question. But you know Warren, not too many people share such beliefs.
Temperature vs depth is very tricky because temperature change slows with depth. You went from one extreme to the other. First you posted 2.7 degrees per km which is probably accurate over 1000 km. Then you went to 2.52 degrees per meter which may be accurate over a meter or two.On the Earth it is 20- 30 degrees Celsius per Km for the first few kilometers but by 200 km it is estimated to be 0.3 degrees.
Although it was not your purpose you are making a great case for ice at depth in lunar cold traps. Even at 2.52 degrees per meter cold traps could be below 273 degrees Kelvin at almost 100 meters.
The simple fact is we need more data.
Yes Warren, I too appreciate "The Emperor's New Clothes" and since 1837 that simple story by Hans Christian Andersen has taught the lesson of how some folks in various leadership positions don't want to appear foolish or think too deeply or ask any questions at all about the obviously nonsensical behavior and illogical proclamations of their Grand Pooh-bah. From such grandiose and easily duped Grand Pooh-bahs we get tragic wars, bankrupt nations, misdirected space programs, and various other types of goofy zig zagging national policies.Now, some pretty serious scientists have repeatedly tried to make the point that the Moon appears to have more than enough water and volatiles to meet our space exploration and in-situ resource utilization needs. Further human field work research to prioritize the tapping of the strategically located Lunar water, volatiles, and other resources would be the logical and commercially smart thing to do, if logic and commerce had anything to do with the vague blind alley asteroid and Mars space policy formulated and articulated by our Grand Pooh-bah.Unfortunately, we space cadets are faced with the little child's task of crying out loudly and repeatedly that the Grand Pooh-bah's space policy's nonexistent clothes are revealing too much of the embarrassing nakedness of a vacuous Solar System exploration architecture which is not based on space commerce, Lunar geology, and the many joys of water where you need it. The water and volatiles that exist both in the Moon and in its polar surface areas will be used by some nation, or group of nations, to make the Moon into the prettiest rocket propellant station imaginable and to make that generous gift even commercially sweeter, Luna has just about the best possible location to efficiently service many local and far voyaging spacecraft. Unfortunately, our current Grand Pooh-bah continues to display his disdain about the commercial prospects of our lovely and resource rich Moon. We Americans routinely install a new Grand Pooh-bah every four or eight years, so hopefully we will eventually get a Grand Pooh-bah that is actually interested in science instead of displaying an ongoing dismal ignorance about what is needed for a functional and commercially robust space exploration architecture.
... so what? Are we looking for life or not? Or is it all about pork ...
Yes Warren, I too appreciate "The Emperor's New Clothes" and since 1837 that simple story by Hans Christian Andersen has taught the lesson of how some folks in various leadership positions don't want to appear foolish or think too deeply or ask any questions at all about the obviously nonsensical behavior and illogical proclamations of their Grand Pooh-bah. From such grandiose and easily duped Grand Pooh-bahs we get tragic wars, bankrupt nations, misdirected space programs, and various other types of goofy zig zagging national policies.Further human field work research to prioritize the tapping of the strategically located Lunar water, volatiles, and other resources would be the logical and commercially smart thing to do, if logic and commerce had anything to do with the vague blind alley asteroid and Mars space policy formulated and articulated by our Grand Pooh-bah.Unfortunately, our current Grand Pooh-bah continues to display his disdain about the commercial prospects of our lovely and resource rich Moon. We Americans routinely install a new Grand Pooh-bah every four or eight years, so hopefully we will eventually get a Grand Pooh-bah that is actually interested in science instead of displaying an ongoing dismal ignorance about what is needed for a functional and commercially robust space exploration architecture.
....The links to the data and leaked studies showWhy a decade of HLVs (Constellation and SLS) did not solve NASA $$$ problems, but depot centric with a LEO ZBO Depot and Smaller LVs Will free up cash for Flexible Exploration ....
Quote ... so what? Are we looking for life or not? Or is it all about pork ...I thought we were looking for a place to live so to spread the risk of living in one place, and for resources with which to generate wealth in order to live comfortably. But we need more data. ...What would be the keystone piece of data about the Moon? Do we need to know whether or not liquid water exists at some depth, or is it enough to know whether or not near surface ice exists in the polar craters? Do we need to know whether or not mankind on the moon will spread across the surface living in surface habs, like houses, or will bore down under the protection of the surface living in underground (?) cities. ...But do we need to know this next? If so, then how do we find out? Can it be done remotely or do we need to dig, drill or blast? Where should we look, and how deep should we look irrespective of the required technology and equipment? If this is not next on the agenda, what is?
Quote ... so what? Are we looking for life or not? Or is it all about pork ...But we need more data. ...But do we need to know this next? If so, then how do we find out? Can it be done remotely or do we need to dig, drill or blast? Where should we look, and how deep should we look irrespective of the required technology and equipment? If this is not next on the agenda, what is?
Quote from: HappyMartian on 07/30/2012 08:13 amYes Warren, I too appreciate "The Emperor's New Clothes" and since 1837 that simple story by Hans Christian Andersen has taught the lesson of how some folks in various leadership positions don't want to appear foolish or think too deeply or ask any questions at all about the obviously nonsensical behavior and illogical proclamations of their Grand Pooh-bah. From such grandiose and easily duped Grand Pooh-bahs we get tragic wars, bankrupt nations, misdirected space programs, and various other types of goofy zig zagging national policies.Further human field work research to prioritize the tapping of the strategically located Lunar water, volatiles, and other resources would be the logical and commercially smart thing to do, if logic and commerce had anything to do with the vague blind alley asteroid and Mars space policy formulated and articulated by our Grand Pooh-bah.Unfortunately, our current Grand Pooh-bah continues to display his disdain about the commercial prospects of our lovely and resource rich Moon. We Americans routinely install a new Grand Pooh-bah every four or eight years, so hopefully we will eventually get a Grand Pooh-bah that is actually interested in science instead of displaying an ongoing dismal ignorance about what is needed for a functional and commercially robust space exploration architecture. Oh really?Quote above leaves in sentences with GPB: Grand Pooh-bahGPB circa 2001-2009 along with the same Congress and forced NASA to build a HLV (Constellation)--throwing out the depot centric architecture. The budget impact of this choice was ~$3B/year. Robotic missions?!The links to the data and leaked studies showWhy a decade of HLVs (Constellation and SLS) did not solve NASA $$$ problems, but depot centric with a LEO ZBO Depot and Smaller LVs Will free up cash for Flexible Exploration GPB circa 2009- threw out Constellation, but *Congress* mandated the 70 to 130 metric tonne LV SLS as part of a compromse--no cash savings. SLS => something << envisioned HSFThe great news for those at NASA who want to start addressing the key Challenges and developing Exploration Hardware is that SLS now has a half life of 4 months. This will free LV dollars for hardware to explore for water and to start working on technologies for other BEO missions.Visiting an asteroid is only a step in the process and has nothing in common with the Constellation flags and footprints 2X/year 6 day lunar sorties. A asteroid mission requires most of the technologies needed for Mars, but with substantially less energy required. Think of the asteroid mission as a lunar flyby--a step in the overall process.But its flexible, if one does find a economically retrievable resource.....asteroid or lunar or ....One remaining key to the puzzle is a reasonable, cheap yearly IMLEO required by NASA to aid the so called 'commercial' lv sector, because as we all know, increasing the flight rate reduces costs. Again, this is accomplished by removing unneeded product lines, and using the cash for BEO hardware.Most people at NASA want to move *forward* to the proper, flexible architecture.
Quote from: muomega0 on 07/30/2012 01:50 pm....The links to the data and leaked studies showWhy a decade of HLVs (Constellation and SLS) did not solve NASA $$$ problems, but depot centric with a LEO ZBO Depot and Smaller LVs Will free up cash for Flexible Exploration ....Hi muomega0!See the comments by Removed User« Reply #110 on: 12/29/2011 08:49 PM »His post is slightly below the one you referenced.Cheers!
Quote from: aero on 07/30/2012 01:33 pmQuote ... so what? Are we looking for life or not? Or is it all about pork ...I thought we were looking for a place to live so to spread the risk of living in one place, and for resources with which to generate wealth in order to live comfortably. But we need more data. ...What would be the keystone piece of data about the Moon? Do we need to know whether or not liquid water exists at some depth, or is it enough to know whether or not near surface ice exists in the polar craters? Do we need to know whether or not mankind on the moon will spread across the surface living in surface habs, like houses, or will bore down under the protection of the surface living in underground (?) cities. ...But do we need to know this next? If so, then how do we find out? Can it be done remotely or do we need to dig, drill or blast? Where should we look, and how deep should we look irrespective of the required technology and equipment? If this is not next on the agenda, what is?Your line of thinking here is pretty good.My indictment of NASA's efforts over the last forty years has been summarized as the preference for profit over accomplishment. Although the word "pork" does not generally cross my lips in this regard, I am not unaware of the concept.We are looking for a place to attempt the experiment of living off planet. That's "we", as in we who are looking for that place to live. Water is one of those resources which could enable wealth generation, if a lot of other things go right. Water might be that "keystone piece of data" for Luna. It will be easier to live on the surface, even if we have to use some meters of regolith for radiation shielding. Windows and distant views are crucial for most people, and quite enticing if the views would be alien and wild.I think we do need to know more about that water next. Unfortunately, the current Pooh-bah and the aspiring Pooh-bah are not interested in Luna, thus have no interest in searching for a site for an outpost.
....Hap, I knew this would happen. Thanks a lot. 1000 words between you all, and the word "liquid" appears nowhere. Let's leave the Presidential politics out of it, please. There is the Space Policy subforum for that if you like. If you must discuss politics, then let's talk about the scientific politics of the astrobiology and planetary science community. Why is it politically incorrect to discuss the possibility of life on the Moon? Why is it career suicide to discuss the possibility? What happened to the ISRO leak that Chandrayaan found "signs of life"? There was no follow up. It disappeared down a black hole. E.g., the latest article quoting a lot of astrobiology rock stars: no mention of the Moon.http://www.guardian.co.uk/science/2012/jul/29/alien-life-enceladus-saturn-moon
.....True, but for the practical purposes of this thread, we are only interested in the top 10 to 100 meters of the surface. It's not clear to me that there is a sharp dogleg in the thermal gradient where it drops down to 20 K/km immediately after the first 2 meters. I'm still researching this issue. Main point remains that it's possible, indeed likely, that liquid water in certain circumstances may reach as high as the base of the regolith is some locations. ....
Quote from: Warren Platts on 07/30/2012 08:27 pm....Hap, I knew this would happen. Thanks a lot. 1000 words between you all, and the word "liquid" appears nowhere. Let's leave the Presidential politics out of it, please. There is the Space Policy subforum for that if you like. If you must discuss politics, then let's talk about the scientific politics of the astrobiology and planetary science community. Why is it politically incorrect to discuss the possibility of life on the Moon? Why is it career suicide to discuss the possibility? What happened to the ISRO leak that Chandrayaan found "signs of life"? There was no follow up. It disappeared down a black hole. E.g., the latest article quoting a lot of astrobiology rock stars: no mention of the Moon.http://www.guardian.co.uk/science/2012/jul/29/alien-life-enceladus-saturn-moonWarren, the topic of this thread is Liquid Water IN The Moon!, not life in the Moon.
I am willing to encourage folks to drill deep for that liquid Lunar water, and have done so in some of my previous posts, . The current Pooh-bah and the Pooh-bah wannabe don't seem inclined to do any drilling on the Moon for liquid water or evidence of life. Luckily, a bipartisan Luna first attitude in Congress seems to have us headed back to the Moon, and once we eventually get there we will do some drilling, and maybe even some very deep drilling for liquid water. Yep, for water, and maybe even life, we should drill deep and not just be "interested in the top 10 to 100 meters of the surface".
"Back in 1998, Onstott made the astonishing discovery that bacteria can thrive in pockets of hot water miles underground far below the depth at which living organisms were known to exist before. Ever since then, he's been spending his summers thousands of feet beneath the earth, in the bowels of South Africa's deepest gold mines, prospecting for other kinds of life in this lightless, hidden biosphere."And, "To prove the critters were truly worms from hell (rather than worms just visiting hell), Onstott and Borgonie had to tap into veins of water that had never been exposed to air. Sure enough, they found worms there as well."From: Could 'Worms from Hell' Mean There's Life in Space? By Michael D. Lemonick Wednesday, June 08, 2011At: http://www.time.com/time/health/article/0,8599,2076281,00.htmlDrill many kilometers deep into the Moon and find "veins" of liquid water and maybe life as well.Cheers!
{snip}That is so awful it's making me begin to get suspicious that the astrobiology rock stars really don't want to find life on another world. Maybe they're afraid that once they find it, the funding will dry up, so a nice 30 year mission to the Far Side of the Solar System is a good way to keep the cabbage flowing. But that's being really cynical on my part. We should have HSF capability to Lunar surface within the decade (it's still the law of the land to have a man on the Moon by 2020). We should start developing drilling technology now. {snip}
...So long as the President does not know the project is there he will not bother to cancel it.
That is so awful it's making me begin to get suspicious that the astrobiology rock stars really don't want to find life on another world. Maybe they're afraid that once they find it, the funding will dry up, so a nice 30 year mission to the Far Side of the Solar System is a good way to keep the cabbage flowing. But that's being really cynical on my part.
Until then NASA has to quietly develop landers, prospecting equipment, drills and refining machines. So long as the President does not know the project is there he will not bother to cancel it.
The exploration technology budget was radically large.
Speaking as an astrobiologist (though not yet a rock star), I have a hard time conceiving of an astrobiologist who didn't want to find life on another world- aside from the nice benefit of having your name immortalized in history as That Guy Who Found Aliens, finding exolife would represent just the start of funding- after all, you're going to need multiple samples, a thorough investigation into the ecosystem of the organisms, lots and lots of gene sequencing, assuming there are genes to be sequenced. The reason Enceladus is getting a lot of attention is because we know with absolute certainty that there is both liquid water and organics there (although personally I'm skeptical that there is enough chemical energy in Enceladus's hydrothermal systems to support life, but I certainly could be wrong).The problem with going after the Moon for astrobiology is that, truth be told, it's not just a matter of following the water- you also need a lot of organics (and easily assimilated organics at that), and a source of energy. Organics have only been definitively detected in relatively trace amounts on the Moon's surface, and there is no reason to suspect that they'll necessarily be found in the subsurface (as they are believed to the result of micrometeorite and solar wind deposition). And as for energy, terrestrial biology uses a relatively narrow range of sources (although it's still surprisingly wide by everyday standards)- the most likely metabolic pathway for the Moon, based on simple availability, would be the reduction of iron, but you'd eventually run out of of Fe(III) to reduce, since there's no volatile oxygen available to reoxidize the Fe(II) and cycle it. It doesn't help that the Moon (at least at the surface) is predominantly silicon dioxide, which is about as biologically inert and inaccessible as you can get.The terrestrial deep subsurface bacteria mentioned earlier get by through an extremely slow metabolism (they may not reproduce for centuries, and it has been suggested that they may be effectively immortal), and by (we think) metabolizing high energy compounds produced by radioactive decay. And even then, the colonies that support nematodes are specifically mentioned as not being entirely isolated from the surface biosphere.Bottom line, while life deep in the Moon can't be ruled out- we've found stranger things, after all- but it's much, much more of a stretch compared to Mars (where water and organic carbon are known to have existed in the past, and may still exist in some form), Europa (strongly suspected to have water and probably organics), and Enceladus (definitively known to have water and organics).
...Speaking as an astrobiologist (though not yet a rock star), I have a hard time conceiving of an astrobiologist who didn't want to find life on another world- aside from the nice benefit of having your name immortalized in history as That Guy Who Found Aliens, finding exolife would represent just the start of funding- after all, you're going to need multiple samples, a thorough investigation into the ecosystem of the organisms, lots and lots of gene sequencing, assuming there are genes to be sequenced. The reason Enceladus is getting a lot of attention is because we know with absolute certainty that there is both liquid water and organics there (although personally I'm skeptical that there is enough chemical energy in Enceladus's hydrothermal systems to support life, but I certainly could be wrong).The problem with going after the Moon for astrobiology is that, truth be told, it's not just a matter of following the water- you also need a lot of organics (and easily assimilated organics at that), and a source of energy. Organics have only been definitively detected in relatively trace amounts on the Moon's surface, and there is no reason to suspect that they'll necessarily be found in the subsurface (as they are believed to the result of micrometeorite and solar wind deposition). And as for energy, terrestrial biology uses a relatively narrow range of sources (although it's still surprisingly wide by everyday standards)- the most likely metabolic pathway for the Moon, based on simple availability, would be the reduction of iron, but you'd eventually run out of of Fe(III) to reduce, since there's no volatile oxygen available to reoxidize the Fe(II) and cycle it. It doesn't help that the Moon (at least at the surface) is predominantly silicon dioxide, which is about as biologically inert and inaccessible as you can get.The terrestrial deep subsurface bacteria mentioned earlier get by through an extremely slow metabolism (they may not reproduce for centuries, and it has been suggested that they may be effectively immortal), and by (we think) metabolizing high energy compounds produced by radioactive decay. And even then, the colonies that support nematodes are specifically mentioned as not being entirely isolated from the surface biosphere.Bottom line, while life deep in the Moon can't be ruled out- we've found stranger things, after all- but it's much, much more of a stretch compared to Mars (where water and organic carbon are known to have existed in the past, and may still exist in some form), Europa (strongly suspected to have water and probably organics), and Enceladus (definitively known to have water and organics).
...having your name immortalized in history as That Guy Who Found Aliens...
Bottom line, while life deep in the Moon can't be ruled out- (1) we've found stranger things, after all- but it's much, much (2) more of a stretch compared to Mars (3) ... Europa ... and Enceladus ...
Quote from: KelvinZero on 07/31/2012 03:49 amThe exploration technology budget was radically large.Yep. Most people who can't understand why anyone would be against SLS seem to be completely unaware of what they gave up to have it.
5. Your point about iron reducing forms running out of iron is well taken, but I was thinking the most likely form would be methanogens feeding off of primoridial carbon dioxide and hydrogen released by the serpentinisation of olivine. (Alternatively, they could get hydrogen from water, and release oxygen--and this could in turn reoxidise Fe(II) and cycle it.) These are the sorts of organisms that live deep within the Earth's basalts (which are primarily composed of olivine). And there is actually a bit of empirical evidence to support this view: there is a mysterious diurnal pulse of methane that the Apollo science packages consistently detected; this is consistent with methanogens releasing methane that slowly makes its way to the surface. During the night it accumulates in the regolith, and then when warmed up by the Sun, it is released to the Lunar exosphere.Any thoughts you have on this subject are very welcome spacermase. Astrobiological expertise is definitely in short supply around here!
Actually, your serpentinization hypothesis is really intriguing- it's not something that had occurred to me, but you are correct, that would be entirely viable (although Fe cycling works better if you have sulfur available to act as an intermediary- the subglacial ecosystem I work on uses exactly that system, and has been stable for the last three million years or so despite being more or less cut off from the rest of the biosphere). The one tricky thing with it, however- and this has been a major bugaboo with the much-debated Martian methane findings- is that serpentinization can also generate methane abiotically. Either way, though, it does definitely suggest the presence of liquid water.Additionally, it occurred to me today that this could actually be a great opportunity for collaboration between lunar and Mars science- it is my personal suspicion, one that is shared with many others in my field, that if there's anything still kicking around on Mars, it's probably going to be buried either in the deep subsurface, or underneath the polar icecaps. Therefore, if we're going to go hunting for Martians, we're going to need some pretty serious drilling equipment, designed for non-terrestrial environments. I think you could make a good argument for the same approach on the Moon (if to practice for Mars, if for no other reason), and if any Selenites happen to serendipitously turn up, so much the better. (Although, with that said, a major obstacle with the previously mentioned idea of life being seeded from Earth on the the Moon occurred to me as well- on Earth, microbes probably infiltrated the deep subsurface using groundwater; on the Moon, no such route would be available, so anything that managed to make it to the Moon's surface would be pretty much stranded there until it either starved or was cooked. Alternatively, if lunar life exists, it may have a separate indigenous origin (which admittedly, from the astrobiological perspective, would be all kinds of awesome)- but that gets into the debate on how easy is it for life to form (do you just need water, organics, and energy, or is life more finnicky than that?), and we really don't know enough to say one way or the other).
...it is my personal suspicion, one that is shared with many others in my field, that if there's anything still kicking around on Mars, it's probably going to be buried either in the deep subsurface, or underneath the polar icecaps.
if lunar life exists, it may have a separate indigenous origin (which admittedly, from the astrobiological perspective, would be all kinds of awesome)- but that gets into the debate on how easy is it for life to form (do you just need water, organics, and energy, or is life more finnicky than that?), and we really don't know enough to say one way or the other).
The link between animal's blood salinity, and that of the oceans is more than a coincidence.
An alternative genesis hypothesis would be that life began in the deep subterranean locations, then spread to the surface. I have not heard of such a hypothesis before,
Of course, life needs an energy source, and the subterranean genesis hypothesis could only work if a "serpentinization of olivine" process, or a similar process, was the first process to produce life, which then spread thruout the planet.
Today, the organisms which "live deep within the Earth's basalts" are more considered to be extremeophiles, and do not represent the vast majority of Earth's life. http://www.sciencemag.org/content/270/5235/377.short
It doesn't seem to me that these guys, who live 1500m below ground, were the first to evolve here on Earth.
Plus, consider the probable mass of these organisms, and compare to the mass of surface based organisms. They probably represent a small proportion of Earthly life by mass, without some proof to the contrary.
For me, the migration of life from cushy environments to extreme environments seems more likely, and I'd say that if life began on Mars, that it began in those oceans, and then possibly migrated to the deep places, time permitting. If life came to be on Mars in the same way it is thought to have come to be on Earth, then those oceans would have been teeming with life for a sufficient number of millenia for it to have migrated to the deep levels.
This means that the sedimentary beds of those ancient oceans should be teeming with fossils. This suggests to me that looking for fossils in these areas should be the first thing to be done.
Might there not be an isotopic distinction between biotically mediated serpentinogenic methane versus abiotically mediated methane? I think I read somewhere that if the methane on Mars is biotically generated, it should be depleted in heavy carbon (C13). As for methane being prima facie evidence for the existence of water, isn't it also the case that we should expect some primoridial methane from the original dust clouds that formed the planets? Or would such primoridial methane get mostly pyrolized?I agree that this potentially offers a great opportunity for collaboration between Mars and Lunar science. But tell us, please: what really happens when you're sitting around talking shop over beers and someone brings up the possibility of life on the Moon? Isn't there a lot of eye rolling. I mean if a graduate student wanted to work on that project, he or she probably might have a hard time getting a job once out of school? As for how life originally got down there, I figure after the late heavy bombardment, as the Lunar surface cooled there must have been a brief period where liquid water was stable on the surface, and life might have snuck into the interior at that point.And regarding the possibility of independent origin, how would we know for sure it was an independent origin, unless it was wildly different. I mean how do we know for sure that the Achaea are not the result of an independent origin?
Spacermase, am I correct that hydrothermal vent origins enjoy no consensus at all? From my reading it appears that the present understanding is that they are a destination site of a range of specifically adapted thermophillics from some other origin site, rather than the origin site of everything. Also, is there any consensus on whether the earliest common ancestor was a thermophile as opposed to a nonthermophile? Lastly, does anyone at all subscribe to cryophillic origins?
freezing of water can concentrate impurities, and at least 7 amino acids and 11 nucleotides have been synthesized in this fashion.
Actually, your serpentinization hypothesis is really intriguing- it's not something that had occurred to me, but you are correct, that would be entirely viable (although Fe cycling works better if you have sulfur available to act as an intermediary- the subglacial ecosystem I work on uses exactly that system, and has been stable for the last three million years or so despite being more or less cut off from the rest of the biosphere).
Troilite is a rare iron sulfide mineral with the simple formula of FeS. ...Troilite is the most common sulfide mineral at the lunar surface. It forms about one percent of the lunar crust and is present in any rock or meteorite originating from moon. In particular, all basalts brought by the Apollo 11, 12, 15 and 16 missions contain about 1% of troilite.
1. Oh, yeah, there would almost certainly be obvious isotopic fractionation. In fact, the Tunable Laser Spectrometer on Curiosity was designed with doing exactly that type of analysis in mind. Same technique should work for lunar methane as well.2. In answer to your question, there would probably be some resistance, just because at first glance it seems pretty out there (astrobiologists in general are biased towards places where there are or were, oceans, for better or for worse); however, on the other hand, I've seen colleagues make a very convincing case for life in the upper atmosphere of Venus, and compared to that, a hypothetical lunar aquifer would be pretty darn hospitable and comfy. So yeah, if you could make a good argument for it, backed with say, data on the methane pulses, plus probably a good model for methane production, I don't think it would have much negative effect on your professional reputation. In fact, about the only thing that will really draw the ire of our community is if it involves UFOs.3. Regarding independent origin and Archaea- there's pretty good phylogenic evidence that we and Archaea have a common ancestor; however, as it was pointed out at the last conference I was at, in the early days of life swapping DNA/RNA/other chemical messengers was absolutely rampant, and as such, clearly defined species as we know them didn't really exist yet. The upshot of that is that you could have had a multitude of independent origins, and the resulting lifeforms "interbred" so much that they eventually formed a more-or-less homogeneous population that gave rise to the current lineage.
Although this discussion has - as ever - drifted into the strange world of US politics, it has at least not gone far down the road followed by the 'MERs photographed organisms on Mars' enthusiasts! Without inviting either subject into our current discourse, could we turn our attention to the ways that biological material might practically be identified?My first thoughts would be that chemical remnants of organisms should persist far longer than microscopic (or larger) remains, and that bulk examination of soils for unexpected chemistry would be the way forward. I suspect that the best way to gather samples would be by unmanned spacecraft - far less forward contamination would occur as compared to using astronauts. Lunar fines, like all powders, have enormous surface area compared to their mass, and I think that it is in such materials that we should be looking for the evidence of biology. Note, please, that I'm at no point suggesting that currently living organisms will readily be found by such means, but that instead we should be looking for the chemical signatures left by biological material. The twin Holy Grails of that approach might well be the identification of biologically inspired molecular 'handedness' or of preferential use of isotopes of common elements.So, how to do it? A series of trenches in polar cold traps?
Attache article on archeae living on basalt and water.re: moon collisions: http://www.technologyreview.com/view/428628/moon-formed-in-interplanetary-hit-and-run/
However, with the recent discovery by an undergraduate student at Brown University of unusual, Lunar volcanic glass beads containing water at the ppt level within pristine, pre-eruptive mantle sampled from the Lunar orange soil recovered by Apollo geologist Harrison Schmitt--a level about the same found in Earth mantle emerging from mid-oceanic spreading zones on Earth--it is now clear that there are large amounts of endogenous water deep within the Lunar interior.
The general astrobiological implications are certainly interesting. ... We should go and look for all these things astrobiological.
And here's an early paper on methane on the Moon. They were surprised at how little the concentration was, give that the measured concentration was about the same as argon36, yet the solar wind flux of carbon was estimated to be an order of magnitude more than the solar flux of argon. It also reminded me that identifying the C13H4/C12H4 is not straightforward, since ammonia (NH3 also has a molecular weight of 17 (as does CH3D).I guess there's nothing mysterious about the pulse: a lot of gases condense during the night, and are then released as the ground gets heated up by the terminator. http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1975Moon...14..159H&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdfAttachments* asdfiwelwkerj.pdf (765.56 KB
....Instead I see a synergy here. As noted the system have seen early large hypervelocity impactors that would mean a preserved record of early geology and biosphere of mostly Earth but also Mars on the Moon. We should go and look for all these things astrobiological.
Testing for meteoric material in the Lunar regolith should actually be remarkably simple - so long as we're *not* looking for biologically interesting stuff! Clearly, there are a number of origins possible for iron in lunar soils, so the next step might be to actively search for nickel-iron nuggets, which should reduce the overall estimates for meteoric material somewhat. To do that, you'll need a lander which can actively search for magnetic material - again, not to difficult a process (the MERs found nickel-iron meteorites on Mars just by driving up to them - how many fragments did they miss, I wonder!).
NASA isn't giving up on Mars. It may have failed to sell the Administration on a big-ticket exploration of Mars in the fiscal year 2013 budget round, but NASA is now undertaking a “reformulation” of its Mars Exploration Program. Next month, the ad hoc Mars Program Planning Group (MPPG), chaired by one-time NASA official Orlando Figueroa, will report to NASA leadership on how robotic exploration of Mars might “remain responsive to the primary scientific goals” of the decadal survey while being “consistent with the President's [2010] challenge of sending humans to Mars orbit,” according to the MPPG Web site. In other words, planetary science would be riding human exploration's coattails to Mars in the FY 2014 budget request.
“That is fraught with danger,” Christensen says. “If you attach yourselves to human exploration,” Bagenal says, “you end up tailoring your science to address the needs of human exploration. Then they change their mind. The lunar people have been down that road several times.” ... And then there is the question of just what science would be both consistent with sending humans to Mars and responsive to the decadal survey. Not a lot, it turns out, at least not for putting astronauts in orbit by the 2030s. “The emphasis is mostly on safety and implementation,” says Carr, who co-chaired a group advising NASA's MPPG. “It's very different from scientific knowledge.”
....Although I think astrobiology is a fascinating subject, the ulterior political motive here is to head off the Mars astrobiologists at the pass and point out that the Moon is as likely to harbor life as Mars--and that such life will be more accessible for less money than manned missions to Mars. So if astrobiologists really want an HSF program that will actually be able to deliver their Holy Grail--alien life in a petri dish--then they should get behind a serious effort to return to the Moon permanently, set up the research station, get some game-changing ISRU going, and start drilling some holes....
Besides the recent reassessment of initial water content of mantles being the same for the Earth-Moon system, the recent assessment of the martian mantle over time by way of martian meteorites found similar levels.
But there is a problem with this model. [the slow impact model] The silicate surfaces of both the Moon and the Earth have a similar isotopic signature indicating that they must have formed from the same stuff. But in a slow, grazing impact, most of the debris that ends up in orbit and forms into the Moon comes from the Mars-sized impactor, which is unlikely to have had the required isotopic signature. That's a major problem.
While I generally agree with spacermase, as for methanogens, and I know I am fairly alone in making this point, I have to disagree here. Phylogenetic analysis predicts that they [methanogens] arose after Earth atmosphere oxygenated, from the aerobic metabolism of methanophiles. (I'll dig up references if asked, but it is late here.)
Hence ~ 50 % of evolution (on an as of yet uncalibrated clock) happened before modern metabolisms diverged.
The initial onset of translation could thus have produced a positive feedback cycle that accelerated its own evolution (Figure 5). The transition from a primitive translation system to a sophisticated one may have been not only rapid but also deterministic.
Although the paper is an important contribution, it will require significant revision in several areas. The most significant omission is supportingdocumentation.
The paper creates, perhaps unwittingly, the impression that ancestry values equate strongly with actual historical age. ... Thus, the reader should be cautioned about this potential limitation of the ancestry values.
While we prefer to view the origin of life as a process that began with the formation of the solar system and endedwith the divergence of the Last Universal Common Ancestor, the common view is that the origin of life was a single event in time.
Clues to the composition of Earth's pre-biotic atmosphere composition as well as surface temperatures prior to the end of late bombardment ca. 3.9 Ga are sparse and inconclusive. ... The addition of abundant biogenic methane to the atmosphere is seen as necessary for providing an adequate greenhouse effect and avoiding a permanent icehouse condition ...The requirement for biogenic methane implies that anaerobic methane-generating organisms (methanogens) would have evolved very early in Earth history, and would have been present in sufficient mass to alter the chemistry of the atmosphere "in time" to compensate for loss of H2 via thermal escape and the inadequacy of CO2 as a sole greenhouse gas.
According to these proposals all differences between Archaea and Bacteria originated at a pre-cellular stage by non-Darwinian means, but they suggest no rationale as to how or why the observed differences between these two groups arose or evolved.
It is of interest in this regard that the analyses of genomic sequences by Lake and coworkers provide evidence that the root of the tree of life does not lie in either Archaea [23] or Gram-negative (diderm) bacteria
We conclude that hydrogenotrophic methanogenesis appeared only once during evolution. ... Given that fossil evidence for methanogenesis dates back 2.8 billion years, a unique origin of this process makes the methanogenic archaea a very ancient taxon.
Increased atmospheric methane was probably partly responsible for the global carbon isotopic shift documented in marine and terrestrial sediments across the Permian–Triassic boundary.
... the origin of anaerobic methane oxidation ca 570 Myr ago reduced methane flux at source, stabilizing Phanerozoic climates.
Previously, assuming that archaebacterial methanogenesis was ancient, this was interpreted as the result of recycling of biogenic methane made by archaebacteria (archaebacterial methanogenesis has exceptionally low 13C : 12C ratios: D13C K30–50‰) by methanotrophic bacteria into organic carbon (Hayes 1983, 1994). Hayes suggested that the rise of oxygen restricted methanogen habitats sufficiently to make their hypothetical contribution quantitatively undetectable less than 2.2 Gyr ago.
Quote from: Torbjorn Larsson, OM on 08/03/2012 01:56 amThe general astrobiological implications are certainly interesting. ... We should go and look for all these things astrobiological. Wow. Now that's what a first post should look like!
Quote from: Torbjorn LarssonWhile I generally agree with spacermase, as for methanogens, and I know I am fairly alone in making this point, I have to disagree here. Phylogenetic analysis predicts that they [methanogens] arose after Earth atmosphere oxygenated, from the aerobic metabolism of methanophiles. (I'll dig up references if asked, but it is late here.)Please do dig up those references, if you would. My understanding of the evolutionary process is as you have described, that methane producers evolved after methanotrophs.
Quote from: Warren Platts on 07/26/2012 07:41 pmHowever, with the recent discovery by an undergraduate student at Brown University of unusual, Lunar volcanic glass beads containing water at the ppt level within pristine, pre-eruptive mantle sampled from the Lunar orange soil recovered by Apollo geologist Harrison Schmitt--a level about the same found in Earth mantle emerging from mid-oceanic spreading zones on Earth--it is now clear that there are large amounts of endogenous water deep within the Lunar interior.The general astrobiological implications are certainly interesting. Besides the recent reassessment of initial water content of mantles being the same for the Earth-Moon system, the recent assessment of the martian mantle over time by way of martian meteorites found similar levels.This would be hard to square with contributions from later impactors. Instead, a reassessment of how modern protoplanetary disk models affect the ice line predicts much the same initial water content for the terrestrials of our system. As opposed to earlier models, it predicts why they are so relatively dry.This is good for habitability here and elsewhere IMO as an off-and-on astrobiology student as time permits. Specifically it tests the validity of the different mantle finds. But it also predicts that the finetuning of water needed for habitability as we know it isn't rare. Enough water for oceans, not too much for continents.
Quote from: Warren Platts on 07/31/2012 06:22 am5. Your point about iron reducing forms running out of iron is well taken, but I was thinking the most likely form would be methanogens feeding off of primoridial carbon dioxide and hydrogen released by the serpentinisation of olivine. (Alternatively, they could get hydrogen from water, and release oxygen--and this could in turn reoxidise Fe(II) and cycle it.) These are the sorts of organisms that live deep within the Earth's basalts (which are primarily composed of olivine). And there is actually a bit of empirical evidence to support this view: there is a mysterious diurnal pulse of methane that the Apollo science packages consistently detected; this is consistent with methanogens releasing methane that slowly makes its way to the surface. During the night it accumulates in the regolith, and then when warmed up by the Sun, it is released to the Lunar exosphere.If we start with the methane observations, they can likely be predicted by the same mechanism that was recently proposed to be able to produce all (arguably) observed methane on Mars, meteorite impact heating. On Mars CO2 contribute, but chondrites have carbons.
5. Your point about iron reducing forms running out of iron is well taken, but I was thinking the most likely form would be methanogens feeding off of primoridial carbon dioxide and hydrogen released by the serpentinisation of olivine. (Alternatively, they could get hydrogen from water, and release oxygen--and this could in turn reoxidise Fe(II) and cycle it.) These are the sorts of organisms that live deep within the Earth's basalts (which are primarily composed of olivine). And there is actually a bit of empirical evidence to support this view: there is a mysterious diurnal pulse of methane that the Apollo science packages consistently detected; this is consistent with methanogens releasing methane that slowly makes its way to the surface. During the night it accumulates in the regolith, and then when warmed up by the Sun, it is released to the Lunar exosphere.
While I generally agree with spacermase, as for methanogens, and I know I am fairly alone in making this point, I have to disagree here. Phylogenetic analysis predicts that they arose after Earth atmosphere oxygenated, from the aerobic metabolism of methanophiles. (I'll dig up references if asked, but it is late here.)
The reason is probably because the needed enzymes are among the most energetically demanding evolved, I hear. Most likely few terrestrial biospheres will have time to evolve methanogens as a niche against lacking photosynthesis and/or suitable geothermal energy sources.
TorbjornTo put this in perspective and use references I have handy, modern whole genome analysis predicts a phylogeny from protein fold families which reach all the way down to the RNA/protein world. On a protein fold clock proxy the RNA/protein world was ~ 20 %, the DNA LUCA was another ~ 20 %, and the diversification into domains the rest. ["The evolution and functional repertoire of translation proteins following the origin of life", Goldman et al, Biol Dir 2010]Hence ~ 50 % of evolution (on an as of yet uncalibrated clock) happened before modern metabolisms diverged.
This is consistent with phylometabolic analyses of non-stereospecific lipid membranes and autotrophic CO2 metabolism, which both predicts robust dual core pathways at a unique root. ["The Emergence and Early Evolution of Biological Carbon-Fixation, Braakman et al, PLOS Comp Biol 2012; "Ancestral lipid biosynthesis and early membrane evolution", Peretó et al, TRENDS in Biochem Sci 2004](One may wonder what early cells lived on. Anoxic photosynthesis akin to modern purple bacteria would be fairly easy to evolve, and it would have liberated cells to form the early phototaxic stromatolites arguably observed.)Instead I see a synergy here. As noted the system have seen early large hypervelocity impactors that would mean a preserved record of early geology and biosphere of mostly Earth but also Mars on the Moon. We should go and look for all these things astrobiological.
As I mentioned earlier; for me, the migration of life from cushy environments to extreme environments seems more likely,
In other words, why would the Mars sized impactor have a substantially different isotopic signature?
Please do dig up those references, if you would. My understanding of the evolutionary process is as you have described, that methane producers evolved after methanotrophs.
The "ancestry values" referred to by Goldman are subject to debate. I'm not sure that I fully understand the concept they are proposing. Fascinating reading.
The author's view is that:QuoteWhile we prefer to view the origin of life as a process that began with the formation of the solar system and ended with the divergence of the Last Universal Common Ancestor, the common view is that the origin of life was a single event in time.That is, the origin of life is a multi-billion year process, not a "single event in time". This notion broadens the scope of the search for the origin so as to become unfocused.
While we prefer to view the origin of life as a process that began with the formation of the solar system and ended with the divergence of the Last Universal Common Ancestor, the common view is that the origin of life was a single event in time.
QuoteClues to the composition of Earth's pre-biotic atmosphere composition as well as surface temperatures prior to the end of late bombardment ca. 3.9 Ga are sparse and inconclusive. ... The addition of abundant biogenic methane to the atmosphere is seen as necessary for providing an adequate greenhouse effect and avoiding a permanent icehouse condition ...The requirement for biogenic methane implies that anaerobic methane-generating organisms (methanogens) would have evolved very early in Earth history, and would have been present in sufficient mass to alter the chemistry of the atmosphere "in time" to compensate for loss of H2 via thermal escape and the inadequacy of CO2 as a sole greenhouse gas.
With a radiative-convective model including new, updated thermal absorption coefficients, we found that the amount of CO2 necessary to obtain 273 K at the surface is reduced up to an order of magnitude compared to previous studies. For the late Archaean and early Proterozoic period of the Earth, we calculate that CO2 partial pressures of only about 2.9 mb are required to keep its surface from freezing which is compatible with the amount inferred from sediment studies. This conclusion was not significantly changed when we varied model parameters such as relative humidity or surface albedo, obtaining CO2 partial pressures for the late Archaean between 1.5 and 5.5 mb. Thus, the contradiction between sediment data and model results disappears for the late Archaean and early Proterozoic.
http://www.ncbi.nlm.nih.gov/pubmed/15876569QuoteWe conclude that hydrogenotrophic methanogenesis appeared only once during evolution. ... Given that fossil evidence for methanogenesis dates back 2.8 billion years, a unique origin of this process makes the methanogenic archaea a very ancient taxon.
You haven't yet commented on the OP, that is, the astrobiological implications of liquid water inside Luna.
Hi Torbjorn. Welcome to the forum.
Was there ever a period when the surface pressure was adequate to favor liquid water on the Moon's surface, once the temperature had cooled down? In other words, had the atmosphere entirely blown away by the time the surface rocks cooled to below 120 C? If so, the life seeded from outer space would have a chance to colonize the Lunar subsurface.
Right, one of the explanations for the 2003 Mars pulse was a meteor impact.
Although our original headline suggested a choice between geology or life on Mars, researchers have since proposed eight different processes that might account for the seasonal plumes, although none of them is without its issues. In addition, there was a ninth option: the researchers behind the original findings were misinterpreting their data, and there was far less methane around than their work suggested.Now, a new study is out that may split the difference. Although it can't account for the full amount of methane suggested by the first paper, it proposes a source of methane that should produce the sorts of seasonal increases seen in the earlier study: a combination of carbon-rich meteors and exposure to UV light.
So, in many ways, these experiments indicate that the combination of UV light and meteor fragments could account for many of the more compelling features of the Mars observations. They do, however, fall short in two ways. One is that they can't explain why the methane in the atmosphere appears to be concentrated over specific regions of the martian surface. The second issue is that the estimates of the total tonnage of meteorites hitting the planet's surface don't seem to bring enough carbon in to fully account for the methane seen in the atmosphere. These data can only fully account for Mars' methane if the more recent estimates of its volume are right and the original report was wrong.
Arguing against that is the ecological one that the water + olivine --> H2 is an ecological niche that predates just about everything.
Also, assigning primitiveness to DNA base pairs (which have no fossils that can be independently dated) is a tricky business. A most parsimonious computer printout is not guarantee that it is 100% the way it happened.
When two independently determined trees mismatch by some branches, they are called "incongruent". In general, phylogenetic trees may be very incongruent and still match with an extremely high degree of statistical significance (Hendy et al. 1984; Penny et al. 1982; Penny and Hendy 1986; Steel and Penny 1993). Even for a phylogeny with a small number of organisms, the total number of possible trees is extremely large. For example, there are about a thousand different possible phylogenies for only six organisms; for nine organisms, there are millions of possible phylogenies; for 12 organisms, there are nearly 14 trillion different possible phylogenies (Table 1.3.1; Felsenstein 1982; Li 1997, p. 102). Thus, the probability of finding two similar trees by chance via two independent methods is extremely small in most cases. In fact, two different trees of 16 organisms that mismatch by as many as 10 branches still match with high statistical significance (Hendy et al. 1984, Table 4; Steel and Penny 1993). For more information on the statistical significance of trees that do not match exactly, see "Statistics of Incongruent Phylogenetic Trees".The stunning degree of match between even the most incongruent phylogenetic trees found in the biological literature is widely unappreciated, mainly because most people (including many biologists) are unaware of the mathematics involved (Bryant et al. 2002; Penny et al. 1982; Penny and Hendy 1986). Penny and Hendy have performed a series of detailed statistical analyses of the significance of incongruent phylogenetic trees, and here is their conclusion:Quote "Biologists seem to seek the 'The One Tree' and appear not to be satisfied by a range of options. However, there is no logical difficulty in having a range of trees. There are 34,459,425 possible [unrooted] trees for 11 taxa (Penny et al. 1982), and to reduce this to the order of 10-50 trees is analogous to an accuracy of measurement of approximately one part in 10^6." (Penny and Hendy 1986, p. 414)
"Biologists seem to seek the 'The One Tree' and appear not to be satisfied by a range of options. However, there is no logical difficulty in having a range of trees. There are 34,459,425 possible [unrooted] trees for 11 taxa (Penny et al. 1982), and to reduce this to the order of 10-50 trees is analogous to an accuracy of measurement of approximately one part in 10^6." (Penny and Hendy 1986, p. 414)
Quote from: TjorbornThe reason is probably because the needed enzymes are among the most energetically demanding evolved, I hear. Most likely few terrestrial biospheres will have time to evolve methanogens as a niche against lacking photosynthesis and/or suitable geothermal energy sources.But an enzyme capable of breaking a high energy bond isn't necessarily more complex or harder to evolve than any other enzyme, or so I would think.
The problem with early photosynthesis is that it requires being close to the surface, probably in a confined space, which would necessarily be transient, not to mention the problem with intense UV radiation.
Similarly, hydrothrmal vents, while protected from UV radiation, probably aren't stable on time scales of tens of millions of years. However, basaltic aquifers would be both protected from UV radiation, be stable at time scales of tens of millions of years, and have a preditable thermal environment, and a ready source of chemical energy.
This is a great example of why we must be cautious using genetic distances as a biological clock. Half of all chemical evolution probably happened during a very short time.
For these reasons, methanogenesis is likely ancient (as suggested by the fossil record) (Brocks et al. 1999),
The n-alkanes are probably the products of a diverse biota of primary producers and heterotrophs. The isoprenoids are derived from photosynthetic microbes with a possible contribution from isotopically light methanogenic Archaea, which are known to yield only small quantities of pristane and phytane relative to total biomass and non-alkanes when pyrolyzed (20). The contrasting depletion of 13C in the kerogen may be attributed to contributions from methanotrophs, as proposed by Hayes (21). However, n-alkanes derived from isotopically depleted membrane lipids of methanotrophs could not be identified in our samples. Furthermore, we cannot discount the possibility that the observed isotopic pattern could also reflect the products of an extinct biochemistry.
Lunar missions over the past few years have provided new evidence that water may be present at the lunar poles in the form of cold-trapped ice deposits, thereby rekindling interest in sampling the polar regions. Robotic landers fitted with mineralogical instrumentation for in-situ analyses could provide unequivocal answers on the presence of crystalline water ice and/or hydrous minerals at the lunar poles. Data from Lunar Prospector suggest that any surface exploration of the lunar poles should include the capability to drill to depths of more than 40 cm. Limited data on the lunar geotherm indicate temperatures of approximately 245-255 K at regolith depths of 40 cm, within a range where water may exist in the liquid state as brine. A relevant terrestrial analog occurs in Antarctica, where the zeolite mineral chabazite has been found at the boundary between ice-free and ice-cemented regolith horizons, and precipitation from a regolith brine is indicated. Soluble halogens and sulfur in the lunar regolith could provide comparable brine chemistry in an analogous setting. Regolith samples collected by a drilling device could be readily analyzed by CheMin, a mineralogical instrument that combines X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques to simultaneously characterize the chemical and mineralogical compositions of granular or powdered samples. CheMin can unambiguously determine not only the presence of hydrous alteration phases such as clays or zeolites, but it can also identify the structural variants or types of clay or zeolite present (e.g., well-ordered versus poorly ordered smectite; chabazite versus phillipsite). In addition, CheMin can readily measure the abundances of key elements that may occur in lunar minerals (Na, Mg, Al, Si, K, Ca, Fe) as well as the likely constituents of lunar brines (F, Cl, S). Finally, if coring and analysis are done during the lunar night or in permanent shadow, CheMin can provide information on the chemistry and structure of any crystalline ices that might occur in the regolith samples.
Geomicrobiology of an Antarctic subglacial brine: A plausible Martian ecosystem The dry valleys of Antartica are host to an assortment of brines at various stages of cryoevaporation ( Lyons et al., 2005 ). It has been suggested that brines formed by similar processes exist on Mars ( Burth and Knauth, 2003 ). Here, we present geomicrobiological data on an Antarctic brine that exists below the Taylor Glacier in the Taylor Valley. Geochemical analyses of subglacial discharge collected at the surface site known as Blood Falls, indicates that the brine is of marine origin and has had limited contact to the atmosphere since it was covered by Taylor Glacier. The brine contains high concentrations of iron oxides (∼3.8 mM), dissolved inorganic (∼50 mM C) and organic carbon (∼400 μM C), and is depleted in sulfate relative to is source waters (SO 4 2−:Cl− ratios in seawater = 0.052; in Blood Falls = 0.035). The microbial diversity associated with this feature, described using molecular and culture techniques, reflects the in situ geochemistry with members known to cycle iron and sulfur compounds (i.e. Thiomicrospria sp., Geopsychrobacter sp., and Desulfocapsa sp.). Combining our geochemical and biological data on the Taylor brine allows for the theoretical modeling of both physical and geochemical constraints on microbially mediated processes in this subglacial system. Importantly, the physical and chemical nature of Blood Falls brine provides a model system for assessing the biological ...
Quote from: JohnFornaro on 08/03/2012 02:37 pmAs I mentioned earlier; for me, the migration of life from cushy environments to extreme environments seems more likely, Agreed.
The requirement for biogenic methane implies that anaerobic methane-generating organisms (methanogens) would have evolved very early in Earth history, and would have been present in sufficient mass to alter the chemistry of the atmosphere "in time" to compensate for loss of H2 via thermal escape and the inadequacy of CO2 as a sole greenhouse gas.
LHB is survivable in models, because cells proliferate and spread faster than realistic impact flows can sterilize. Even crust busters are survivable ~ 1 km down. Life is a plague on a planet.
AFAIK the Moon likely still has a molten active core by the reassessed Apollo seismic experiments. Energy, water and presumably organics is present, possibly resulting in a habitable crust.
"We think the moon is in a general state of global contraction because of cooling of a still hot interior," said Thomas Watters of the Center for Earth and Planetary Studies at the Smithsonian's National Air and Space Museum in Washington, and lead author of a paper on this research appearing in the March issue of the journal Nature Geoscience. "The graben tell us forces acting to shrink the moon were overcome in places by forces acting to pull it apart. This means the contractional forces shrinking the moon cannot be large, or the small graben might never form."
...the similar results and how a calibrated and detailed fold clock fairs. The "very short time" of biological evolution is ~ 0.6 Ga (RNA/protein world) respectively ~ 0.5 Ga (the intense Archaean Expansion period that seems associated with the DNA LUCA) for each 20 % proxy period, leaving ~ 2 Ga for the domain diversification. The mismatch to the real clock is ~ 1 Ga out of ~ 4 Ga, or 25 %.
Well, as I noted, AGW theory has lowered the necessary CO2 with a faint early Sun significantly.
Quote from: Torbjorn Larsson, OM on 08/06/2012 10:51 pmQuote from: JohnFornaro on 08/03/2012 02:37 pmAs I mentioned earlier; for me, the migration of life from cushy environments to extreme environments seems more likely, Agreed.....It's only a uhhhh..... plague on one planet, that we can tell. To me the LHB doesn't really include Mars size impactors, does it? Impactors which turn the crust of both bodies into magma oceans? (ignoring for the moment that Earth didn't get a magma ocean from this impact, as is currently thought) Does that magma ocean not extend down one km? Worse, that model presupposes that life was already existant at that level. I can't imagine a mechanism by which it was driven to that depth in that impact.So I'm having a hard time with this theorizing at the moment.Quote from: TorbjornAFAIK the Moon likely still has a molten active core by the reassessed Apollo seismic experiments. Energy, water and presumably organics is present, possibly resulting in a habitable crust. Ever the grammarian; fixed that for ya. But current thinking is that Luna has a molten interior:http://phys.org/news/2012-02-lunar-reconnaissance-orbiter-reveals-geological.htmlQuote"We think the moon is in a general state of global contraction because of cooling of a still hot interior," said Thomas Watters of the Center for Earth and Planetary Studies at the Smithsonian's National Air and Space Museum in Washington, and lead author of a paper on this research appearing in the March issue of the journal Nature Geoscience. "The graben tell us forces acting to shrink the moon were overcome in places by forces acting to pull it apart. This means the contractional forces shrinking the moon cannot be large, or the small graben might never form."
It's Alive! There's Magma on the Moon Feb 21, 2012At: http://news.discovery.com/space/moon-magma-122102.html"Instead, these findings suggest the moon was not completely molten after it was formed. If this were the case, the moon would not contract strongly enough to suppress the emergence of graben."And, "'Currently, a popular idea for how the moon formed is that it was completely molten in the beginning— after a Mars-size object hit Earth very early in its history, the debris cloud from the surviving material formed the moon,' Watters said. 'This may lend support to alternative scenarios that the moon was not completely molten when it formed, that only part of it was, forming a magma ocean.'" ....
Hi Torbjorn, I'm not wedded to anything here either, except the principle of "follow the water". If it's halfway geologically plausible that liquid water could be found within 1 to 100 meters of the surface, that's some low hanging fruit that we ought to pluck before we go traipsing off to Mars. And positive or negative results aside, the experience gained will prove very helpful and lower the costs IMO when we do in fact go to Mars. In that regard, I came across this intriguing reference:QuoteLunar missions over the past few years have provided new evidence that water may be present at the lunar poles in the form of cold-trapped ice deposits, thereby rekindling interest in sampling the polar regions. Robotic landers fitted with mineralogical instrumentation for in-situ analyses could provide unequivocal answers on the presence of crystalline water ice and/or hydrous minerals at the lunar poles. Data from Lunar Prospector suggest that any surface exploration of the lunar poles should include the capability to drill to depths of more than 40 cm. Limited data on the lunar geotherm indicate temperatures of approximately 245-255 K at regolith depths of 40 cm, within a range where water may exist in the liquid state as brine. A relevant terrestrial analog occurs in Antarctica, where the zeolite mineral chabazite has been found at the boundary between ice-free and ice-cemented regolith horizons, and precipitation from a regolith brine is indicated. Soluble halogens and sulfur in the lunar regolith could provide comparable brine chemistry in an analogous setting. Regolith samples collected by a drilling device could be readily analyzed by CheMin, a mineralogical instrument that combines X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques to simultaneously characterize the chemical and mineralogical compositions of granular or powdered samples. CheMin can unambiguously determine not only the presence of hydrous alteration phases such as clays or zeolites, but it can also identify the structural variants or types of clay or zeolite present (e.g., well-ordered versus poorly ordered smectite; chabazite versus phillipsite). In addition, CheMin can readily measure the abundances of key elements that may occur in lunar minerals (Na, Mg, Al, Si, K, Ca, Fe) as well as the likely constituents of lunar brines (F, Cl, S). Finally, if coring and analysis are done during the lunar night or in permanent shadow, CheMin can provide information on the chemistry and structure of any crystalline ices that might occur in the regolith samples. http://naca.larc.nasa.gov/search.jsp?R=20020074706&qs=Ns%3DLoaded-Date%7C0%26N%3D4294774829....
QuoteThe requirement for biogenic methane implies that anaerobic methane-generating organisms (methanogens) would have evolved very early in Earth history, and would have been present in sufficient mass to alter the chemistry of the atmosphere "in time" to compensate for loss of H2 via thermal escape and the inadequacy of CO2 as a sole greenhouse gas. ... how did they get to the inside of Luna?
BTW, this link was broken for me this morning.
It's only a uhhhh..... plague on one planet, that we can tell. To me the LHB doesn't really include Mars size impactors, does it? Impactors which turn the crust of both bodies into magma oceans? (ignoring for the moment that Earth didn't get a magma ocean from this impact, as is currently thought) Does that magma ocean not extend down one km? Worse, that model presupposes that life was already existant at that level. I can't imagine a mechanism by which it was driven to that depth in that impact.So I'm having a hard time with this theorizing at the moment.
Ever the grammarian; fixed that for ya.
Quote from: GoldmanWhile we prefer to view the origin of life as a process that began with the formation of the solar system and ended with the divergence of the Last Universal Common Ancestor, the common view is that the origin of life was a single event in time.This view makes the OP's speculation even more tentative, I'd say. Theia would have had to undergone this multi-billyun year process, at a survivable depth before whacking the Earth. In addition, there would have had to be a "likely RNA/RNA to RNA/protein genetic/catalytic worlds transformation", as you point out..
I get that such a "clock" has not yet been adequately proposed to explain the Earthly genesis of life. But this "clock" will have to include Luna as well, wouldn't it? First, Theia would have to be found...
Obviously, I'm not suggesting that the methanogens as we know them today are pretty much the original "ur" organisms, but the niche itself is certainly old enough, and is at least as likely as any other niche to be the first one that spawned life. Interestingly, the mysterious "nanobes" that some people think they have found--nano-"bacteria" much, much smaller than ordinary microbes (these are about the same scale as the supposed nanobacteria found in the Mars meteorite)--these are found in deep, subterannean environments.
Who among you kind and gentle readers believe that the Martian meteorite contains compelling evidence of Martian life? Then why do you discount similar evidence of Lunar life?Quote from: Zhmur and Gerasimenko (1999)[We present] the results of the analyses of microphotos of lunar regolith particles published earlier, which confirmed that lunar rock contains fossilized remnants of microbial organisms, that most probably had been functioning in hydrothermal springs.
Quote from: JohnFornaro on 08/07/2012 04:32 pm... how did they [the primitive life forms] get to the inside of Luna?my refs show there is no longer a "requirement for biogenic methane". CO2 would suffice.
... how did they [the primitive life forms] get to the inside of Luna?
As already noted, we find bacteria (and nematodes!) several km down, they migrate in cracks.
I meant that if we have the presumed organics, it would be a habitable zone by definition. You changed the logics.
Quote from: GoldmanWhile we prefer to view the origin of life as a process that began with the formation of the solar system and ended with the divergence of the Last Universal Common Ancestor, the common view is that the origin of life was a single event in time.This view makes the OP's speculation even more tentative, I'd say. Theia would have had to undergone this multi-billion year process, at a survivable depth before whacking the Earth. In addition, there would have had to be a "likely RNA/RNA to RNA/protein genetic/catalytic worlds transformation", as you point out..
I responded on this in my earlier comment, they can't possibly mean that planets aggregating and differentiating is a problem. The Earth-Moon event may have restarted what was already underway, surely.
Organic matter likely has been found on the Moon.
To migrate 1 km over 1 million years (a mere blink in geological time) the average speed would have to be 1 mm/year. This is a rate of about 1/10th of a micrometer per hour.
The creatures have been separated for millions of years and occupy different ecological niches. It would be surprising if they were the same species.
You are still conflating the "Giant Impact" with the "Late Heavy Bombardment". These are two entirely separate events.
Quote from: JohnFornaro on 08/13/2012 02:53 amAs I understand the Theian hypothesis, as modified by the subterranean lunar life hypothesis; Earth had life; Earth was impacted by Theia, and life was transferred to the piece that became the Moon, deep under the magma ocean.Straw man figment of your imagination. Nobody says this. :o If you can find a reference to this, I'd dearly love to see it....
As I understand the Theian hypothesis, as modified by the subterranean lunar life hypothesis; Earth had life; Earth was impacted by Theia, and life was transferred to the piece that became the Moon, deep under the magma ocean.
The geologic era in which abiogenesis likely took place was the early Eoarchean era (between 4.0 and 3.6 billion years ago, i.e. the time after the Hadean era in which the Earth was essentially molten) with abiogenesis occurring between 3.9 and 3.5 billion years ago.
Between 3.8 and 4.1 Ga, changes in the orbits of the gaseous giant planets may have caused a late heavy bombardment that pockmarked the Moon and the other inner planets (Mercury, Mars, and presumably Earth and Venus). This would likely have sterilized the planet, had life appeared before that time.
The prevailing hypothesis today is that the Earth–Moon system formed as a result of a giant impact: a Mars-sized body hitting the newly formed proto-Earth, blasting material into orbit around it, which accreted to form the Moon.[18] Giant impacts are thought to have been common in the early Solar System. Computer simulations modelling a giant impact are consistent with measurements of the angular momentum of the Earth–Moon system and the small size of the lunar core; they also show that most of the Moon came from the impactor, not from the proto-Earth.[19] More recent tests suggest more of the Moon coalesced from the Earth and not the impactor.[20][21][22] Meteorites show that other inner Solar System bodies such as Mars and Vesta have very different oxygen and tungsten isotopic compositions to the Earth, while the Earth and Moon have near-identical isotopic compositions. Post-impact mixing of the vaporized material between the forming Earth and Moon could have equalized their isotopic compositions,[23] although this is debated.[24]
Around the core is a partially molten boundary layer with a radius of about 500 kilometers.[28] This structure is thought to have developed through the fractional crystallization of a global magma ocean shortly after the Moon's formation 4.5 billion years ago.[29]
The Apollo 11 basalts provided one bit of evidence. Cosmochemists found that some chemical characteristics of mare basalts were complementary to those of anorthosites. This suggested that the regions in the deep interior of the Moon where the basalt lavas formed by partial melting were part of the same magma from which the anorthosites formed. Since the mare basalts formed at depths of hundreds of kilometers, the magma must have been hundreds of kilometers thick.
Moreover, nobody as far as I know has ever suggested that life originated on Earth before the hypothetical Theia impacted the Earth; nobody as far as I know has suggested life on Earth would survive the Theia impact.
I never suggested, implied nor stated that the magma ocean created by the giant impact that formed the Moon was only 100 m thick.
It looks like life occurred on Earth after the impact of Theia and the Moon's formation. The magma ocean that was the surface of the Moon was "several hundreds of kilometers" deep. Warren suggests looking in the range of one to a hundred meters for the hypothetical aquifers.
Drilling 1 meter to 100 meters on the Moon...
If it's halfway geologically plausible that liquid water could be found within 1 to 100 meters of the surface...
...for the practical purposes of this thread, we are only interested in the top 10 to 100 meters of the surface.
3. Water oceans formed over the former magma ocean on the Earth; presumably, there were periods when bodies of liquid water also formed on the Moon. If panspermia happens, then life could have been transferred to crater lakes on the Moon during this time.4. Water in crater lakes on the Moon would seep underground bringing living microbes along with it. 5. Then the crater lakes dry up, leaving life forms living underground in sublunarean aquifers.
Many authors pointed out that magma oceans can contain substantial amounts of water...
...estimates for the depth of this magma ocean ranging from about 500 km to full moon melting.
I've been doing some more research trying to tighten up the thermal gradient argument. It turns out there is a radical dogleg in the thermal gradient (K/m) at the regolith/bedrock boundary. The difference has to do with the radically different thermal conductivities (W/mK) of regolith versus solid rock: regolith thermal conductivities are on the order of 0.01 W/mK, whereas that for basalt is more like 1.7 W/mK. ...So the thing to do is:(a) find a spot where the regolith is extra deep--at 30 meters, it would be warm enough for liquid water under most scenarios;(b) find a spot where the radioactivity is higher, such the Procellarum KREEP Terrane (a.k.a., the PKT)--higher radioactivity entails higher heat flux and hence higher thermal gradient, in which case, liquid water could possibly be found at a depth of only 20 meters.
There has yet to be proposed [By Warren Platts] a mechanism by which the hypothetical aquifers, with water and organics in the amounts and depths that Warren theorizes about, could have started accumulating when the Moon cooled enough. This mechanism needs a start date, a rate of accumulation, a time of accumulation, and a means for testing the hypothesis, short of sending up a drilling rig to ground truth a theory presented to the extent that this theory has been presented.
During Epoch II, which spanned the period from the end of the last magma ocean and the formation of the lunar crust 4.4 Gyr ago, until the tailoff of large impacts, 3.4-3.0 Gyr ago, the lunar atmosphere stochastically fluctuated between an SBE state and thicker environments owing to the effects of vulcanism and impacts.
The "presumably" awaits proof. "If panspermia happens", also awaits proof.
So what? I'm sure you have a point here. Perhaps you should spell it out explicitly.
What is missing tho, is a theory by which the water possibly contained in the Moon's magma oceans condensed and stayed liquid on the surface of the Moon; maintained their temperature and pressure so as to support life; received lifeforms from another body or else underwent abiogenesis; and migrated successfully to the depth of 10m to 100m.
To migrate 1 km over 1 million years (a mere blink in geological time) the average speed would have to be 1 mm/year. This is a rate of about 1/10th of a micrometer per hour. The diameter of most bacteria ranges from about 0.2 to 2 microns. To put this in perspective, the continents on the Earth move at 10 to 100 times faster than this speed.
Microbes have been found as deep as we have looked for them. Five kilometers is the record so far. You seem to be confused about microbes make their way into deep formations. The simplest explanation is they simply move through little channels, cracks and pores.
Quote from: JF4. "Water in the crater lakes" also awaits proof. I don't believe this hypothesis, that liquid water crater lakes are known to have existed on the Moon, is in the published literature. There you go again, putting words in my mouth I never said....
4. "Water in the crater lakes" also awaits proof. I don't believe this hypothesis, that liquid water crater lakes are known to have existed on the Moon, is in the published literature.
And as I said, a million years is a blink in geological and evolutionary time. Therefore, it would be surprising that any organisms on the Moon did not have plenty of time to make the migration from crater lakes to underground aquifers; which if my calculations are correct, the shallowest depths of which are measured on scales of 10 to 100 meters, not 1000 m. The burden of proof is on you to demonstrate the supersurprising idea that organisms wouldn't have a 100,000 years to move 100 meters.
Yeah? So what? What IS your point?!?
And yet again, your intuition fails to capture reality. Name a single "soggy soil" place on Earth that isn't crawling with life.
It is my intuition that if liquid water is found on the Moon at a depth of a hundred meters, then it will be "soggy soil" ....
There was plenty of water available to form crater lakes.
you haven't addressed the temperature, the quantity of water accumulated, or the time during which it may have accumulated.
1500 K > 373 K > 273 K > 250 K > 30 K
I specifically said I didn't know if abiogenesis or panspermia or a combination of the two or neither happened on the Moon.
My claim is that if the sublunarean aquifers are still there, then it's quite likely that they harbor life.
I never said that life on the Moon requires panspermia.
Moreover, your supercillious assertion that the speed of migration estimate I calculated was arbitrarily chosen is either an intentional misrepresentation or a catastrophic misreading of what I wrote: the estimate was an attempt to come up with a reasonable lower bound on migration rates...
John, have you ever heard of the principle of uniformitarianism? Or the Copernican principle? In essence, the idea is that the Earth is not special. The theory is that same laws of physics that happen on the Earth also happen at other places in the universe. This does require the assumption that the universe is somewhat orderly. If you disagree with that assumption, I can respect that, I guess.
The real question if what are you full of.
I was hoping it was something a little more substantive like that we can't go spending money looking for liquid water on the Moon because we haven't yet proved that what we are looking for is there.
We should not go spending money looking for liquid water on the Moon in sublunarean aquifers because the existence of those hypothetical aquifers is not supported by a more complete theory of how they came to be, and how life could have arrived in those aquifers.
1) On the other hand, ALH84001, and others of its class have conclusively demonstrated that (a) material is exchanged between Mars, the Earth, and the Moon, and (b) that these transfer events can happen at low enough temperatures so that any life contained within such rocks would not be sterilized. ...2) Certainly, it is the case that the Moon did not have as much time as the Earth did for abiogenesis to occur; however, we cannot say beyond a reasonble doubt that the Moon did not have enough time for abiogenesis to occur. ...3) Without such a plausible, indigenous source of fresh water and energy, it would indeed be hard to make a case for life in the Moon. But now that such a source has been found, the opposite condition holds: it is now difficult--once one thoughtfully considers the evidence with an open mind--to presume that life could not exist on the Moon! ...4) If the analysis presented here has no irreparable major holes in it (and I see none so far--John Fornaro certainly hasn't pointed out one yet)...
....Many years from now, after this capability has been developed, drill below the Moon's surface and look for life there, if a private group could fund that effort. Do not use public funds at this time for a search for lunar life.
First, thanks for changing your tone of voice.
I pruned back my low signal-to-noise posts...
Pf = Pl X Pg X Pa
John, you've already expressed sympathy for directed panspermia in this thread.
I guess the comment that Lunar aquifers would be "soggy soil" is meant to imply that the permeability of Lunar soggy soils would be so low that life would not have time to migrate into the interior.
[Panspermic] Transfer to the Moon ... call it 90%. So overall, the odds that at least one of the probable thousands of transfers that took place managed to survive look pretty good. Call it 50%. Thus the overall odds of successful panspermia would be 0.9 * 0.5 = 0.45.Time for abiogenesis ... call it 10%.... before Brown, the mantle water concentration was thought to be orders of magnitude less than 1 ppt. ... Assigning a 50% probability is probably conservative.... the probability that life actually would be found within 100 m ... Call it 50%.
Quote from: Warren PlattsI guess the comment that Lunar aquifers would be "soggy soil" is meant to imply that the permeability of Lunar soggy soils would be so low that life would not have time to migrate into the interior. That is incorrect. ... I don't think that liquid water existed in lunar craters long enough to find its way down to those levels. Your theory holds that the lunar atmospheric pressure and temperature allowed this to take place, after the Theian impact event.I think that if there is water ... that it would be "soggy soil" and not an "aquifer".
We are simply not finished looking for life on Mars, therefore we should not use public funding to hunt for it on the Moon. That task can be done much later in time.
Your idea that microbes cannot traverse a muddy lake bottom into a gravelly, underlying aquifer is simply false.
Quote from: Warren PlattsYour idea that microbes cannot traverse a muddy lake bottom into a gravelly, underlying aquifer is simply false.This is a false statement that you attribute to me.
In fact, I'm going to stick my neck out and make a prediction: Ina is located in a region where the regolith is at least 20 to 30 meters thick, probably in a high KREEP zone (higher radioactivity, and there for higher heat flow), and it is in a region that is relatively young and otherwise undisturbed by major impact events.
How Did Ina Form? The bright, rubbled materials on Ida's floor appear to consist of fresh exposures of high-titanium mare basalt, with the regolith removed. The heights of the hills suggest that the regolith is thicker than 12 meters. An alternative is that the surface consists of pyroclastic volcanic materials, or a combination of regolith and pyroclastic debris. The basalts are old, probably as old as the Apollo 11 mare basalts, about 3.5 billion years. Schultz and colleagues suggest that the regolith or pyroclastic layer was blown away by the sudden release of pressurized gases. The subdued ejecta surrounding the structure indicates that the process was not as energetic as an impact, consistent with a gas eruption. Which gases is unknown, but they must have come from deep within the Moon, and collected beneath the surface until their pressure built up enough to suddenly burp out, blowing regolith around, a rare case of wind on the airless Moon. Schultz has found three other features similar to Ina. All are related to structural features associated with linear rilles associated with the Imbrium impact basin. These areas may be places of crustal weaknesses that allow interior gases to escape. Schultz and his coworkers also point out that the Apollo alpha-particle spectrometer gave hints of recent gas releases from the lunar interior. Ina is adjacent to one of the broad regions having elevated polonium-210 alpha particles. Polonium-210, which forms from radon (produced during uranium decay), has a short half-life, so its radon parent must have been released during the past 60 years. Thus, the Moon appears to be leaking gases now, and occasionally does so in bursts, forming or modifying features like Ina.
Here's a pdf that seems to bolster the notion of native lunar water beneath the surface.
{snip}A cool experiment to try would be to release a couple of tonnes of an obviously artificial tracer gas on the opposite side of the Moon and then see how long or if it makes it to the LADEE detector.
In August 2011, planetary scientist Erik Asphaug of Arizona State University published a theory describing the source of the mysterious, mountainous farside lunar highlands: a smaller, short-lived second moon. For tens of millions of years, the moon and moonlet peacefully coexisted. Then, in a slow-motion collision, the moonlet bumped into the moon. Rather than creating a crater, the moonlet pancaked, sending millions of cubic miles of rocky material sliding across the lunar globe. The landslide-like rubble quickly piled up to a depth of tens of miles, Asphaug describes. So I think thats consistent with a deeply porous moon, but obviously there are many ways to generate porosity. Asphaug also notes that a deep, porous crust, as interpreted by the GRAIL team, could have captured water delivered by cometary impacts and that, if coupled with a source of heat, could have provided briefly favorable pockets where life could evolve with the help of materials ejected from Earth.
And with all that porosity will some folks worry a bit less about having a place to dump excess heat from Lunar nuclear and solar thermal electric power plants?
Quote from: HappyMartian on 12/28/2012 12:17 pmAnd with all that porosity will some folks worry a bit less about having a place to dump excess heat from Lunar nuclear and solar thermal electric power plants?Don't see how that follows...
....Thus, it is possible that an impact could cause the catastrophic release of CO2 and H2O at Ina. The resulting explosion would release pressure on adjacent zones causing a cascading chain reaction that could explain the characteristic humpy morphology of meniscus hollows.
Quote from: Warren Platts on 07/25/2013 10:13 pm....Thus, it is possible that an impact could cause the catastrophic release of CO2 and H2O at Ina. The resulting explosion would release pressure on adjacent zones causing a cascading chain reaction that could explain the characteristic humpy morphology of meniscus hollows. Sounds reasonable to me!Do you think there would still be minable H2O/CO2 at or near Ina?
Here's a thought: would fracking work on the Moon? Perhaps a seriously small nuke at the bottom of a deep hole would shake and bake some water vapour out of the interstices of the megaregolith...
We see the traces of tremendous sublunarian disturbances (using the word "sublunarian," here and elsewhere, to correspond to the word "subterranean" used with reference to the earth), and we find some features of resemblance between the effects of such disturbances and those produced by the subterranean forces of our earth;
Here we analyse spectroscopic data from the Moon Mineralogy Mapper (M3) and report that the central peak of Bullialdus Crater is significantly enhanced in hydroxyl relative to its surroundings. We suggest that the strong and localized hydroxyl absorption features are inconsistent with a surficial origin. Instead, they are consistent with hydroxyl bound to magmatic minerals that were excavated from depth by the impact that formed Bullialdus Crater. Furthermore, estimates of thorium concentration in the central peak using data from the Lunar Prospector orbiter indicate an enhancement in incompatible elements, in contrast to the compositions of water-bearing lunar samples2. We suggest that the hydroxyl-bearing material was excavated from a magmatic source that is distinct from that of samples analysed thus far.
Evidence of serpentinization of olivine:http://www.nature.com/ngeo/journal/v6/n9/full/ngeo1909.htmlQuote Here we analyse spectroscopic data from the Moon Mineralogy Mapper (M3) and report that the central peak of Bullialdus Crater is significantly enhanced in hydroxyl relative to its surroundings. ...This is very exciting news.
Here we analyse spectroscopic data from the Moon Mineralogy Mapper (M3) and report that the central peak of Bullialdus Crater is significantly enhanced in hydroxyl relative to its surroundings. ...
In case anyone's interested, here's a copy of the paper I presented at the GS workshop. My approach was to use the debris halo that surrounds Ina to constrain the energetics of whatever phenomenon produced it. It turns out that a CO2-liquid water system has just about the right energy to make it happen: not too violent, not too mild. I can't think of any other phenomenon that could do it. Maybe you can?