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<<Halfway around Mars, Opportunity is exploring clockwise around "Victoria Crater," a bowl about 800 meters (half a mile) across. Cliff-like promontories alternate with more gradually sloped alcoves around the scalloped rim. The impact that dug the crater exposed layers that had been buried.
"The images are breathtaking," said Dr. Steve Squyres of Cornell University, principal investigator for the rovers. "Every promontory we've seen has the kinds of layering expected for ancient wind-blown sand deposits." >>
The above quotation, from the NASA/JPL website following the Martian Rovers, is the first to explicitly state that layering on Mars may be due to wind-blown deposits, instead of their usual claim that they must be due to water-born material.
This make perfect sense considering that we know there are annual planet-wide windstorms that raise a huge amount of dust and redistribute it around a good part of the planet. That'ws a fact. Planet-wide liquid water is still only a hypothosis, a hope, a prayer...
I've been reading Sagan's Cosmos recently and wondering about this question. Actually, there are some hypotheses:
1. Civilisations developing technology (radiostelescopes) also invent ways of destroying themselves (nucelar bombs). They destroy themselves so often, that the number of civilisations co-existing within our galaxy at a given time is about 10. (from Sagan's book)
2. Civilistations concentrate on listening instead of broadcasting due to limited resources/funds. Nobody talks, everybody just listen. (a Polish book)
3. Civilisations capable of detecting Earthlings are very advanced. They are aware of our existence but they do not want to interfere and prefer to observe. (Sagan's book).
4. We are living at the border of a region in space that has been recently cleansed of all life by a violent supernova. Eartlings were too far but other life in the vincinity was destroyed (my humble assumption).
5. There are colonisers gradually proceeding from one system to another but they have not reached us yet - life is common but intelligent life is quite scarce (Sagan's book).
What do YOU think? Which option is most likely and why? Or maybe some other option not mentioned here?
To get the best answer to your question, read "Rare Earth: Why Complex Life is Rare in the Universe"--a sensational work, one of the most excting books I've read in the past 20 years. At Amazon http://www.amazon.com/Rare-Earth-Comple … 367&sr=8-3
However, I found out about something recently that was quite interesting: The "Wow!" signal. In 1977 a researcher working for SETI detected a strong radio pulse coming from the star Tau Sagittarii. This was on a bandwidth in which terrestrial transmitters are forbidden to transmit in. The pulse was so surprising and so similar to what an expected E.T. signal would look like, that the researcher wrote "Wow!" on the computer print out. The signal only lasted for 72 seconds, and nothing like it was ever detected again.
It's possible that it was a terrestrial broadcast or some freak natural event, but it's the closest thing we've ever gotten to a real alien signal. Makes you look up at the stars, smile, and wonder...
Wikipedia link for those who want to learn more: http://en.wikipedia.org/wiki/Wow%21_signal
One of anything can be anything. Intelligence is not a burst of radiation. This was an explosion of some kind. Also, the handwriting of the "Wow" is that of an immature person--someone who would be easily influenced or with an active fantasy.
I hope it's true and not Carbon Dioxide. If it is. Then it would be another reason to go there.
CO2 does not become a liquid until the pressure is over 5 bar. On Mars the atmospheric pressure is way way below that. Solid CO2 directly sublimates to a gas when the temperature goes above -78°C and therefore it would not flow and disturb the surface as seen in the images.
"White Mars" explains that solid CO2 ("dry ice") can be maintained as a solid for two reasons: it is cold enough, and/or, the pressure on the solid CO2 is high enough. Thus, if there is a large block of dry ice under the surface, and it is loosen by a Marsquake, or the local tempersature rises a bit above critical, this can cause a conversion to liquid and gas CO2. The result can be explosive, causing a huge flood of liquid CO2 to course down a cliff face, or hill, ripping everything out of its way just like a torrent of liquid water.
See http://www.velocitypress.com/water_on_mars.shtml near the bottom for a bibligoraphy of articles on thisw subject. Fascinating reading.
<<I wanted to know if anyone could tell me where I can find surface temperatures for Mars during past epochs (any epoch will do except current conditions)? >>
I doubt this is known, although it could be found out by drilling into ice at the poles--the same way they do here on earth. However, the sun was about 25% cooler millions of years ago--at the time Mars might have had liquid water on its surface. So the likelihood is that it is warmer now than it ever was. That does not bode well for ever having had a lot of liquid water.
<<How about we get into the areas of focus that interest them most and use those things as ways to reach them? How about we show them that space is relevant to them? We can do this through many different means, I'm sure we all have some ideas.>>
In my opinion, the cosmic issue on generating interest in a manned Mars expedition is to find alien life. Ideally, that alien life would be an extinct form of BEM, complete with crumbling ruins, extensive literature, odd religions, wierd writing, etc., etc.
NASA is fully aware of this interest. That is one reason why its reports from Spirit and Opportunity are chockablock with hints, suggestions, allusions, and prayers that extensive surface water existed on Mars in the past. One in a blue moon do they drop the aside that many of these clues could have come as well from other mechanisms: the layering may have been caused not by water, but by successive wind-born accumulations, etc.
This "bias" towards free water is much like the bias of left-wingers to the war in Iraq: they have their view, and are completely blind to counter-evidence. Indeed, counter-evidence is not that, but simple heresey. You can't bring it up without being looked at like a blasphemer, a turd in the punch bowl, and certainly not a team player.
But, the unvarnished reality is that Mars probably never had abundant liquid surface water, the planet was probably never warmer than it is now (the sun was even cooler millions of years ago), withiout a liquid iron core to generate a magnetic field and thus create a radiation-shielding van Allen belt, the surface of Mars has been effectively sterilized. True, this does not absolutely rule out microbial life underground, but we can pretty much kiss Bug-Eyed Monsters goodbye.
So what's a good PR department to do to keep the budget flowing? Well, what they're doing now is pretty much it. Keep up people's hopes. Lend technical expertese to Hollywood productions like "Red Planet," and so on--all to help keep the hope alive that something really wierd is hidden on Mars, waiting for intrepid American pioneers to uncover. (Remember the evocative poster put out by Boeing? Two astronauts are surmounting a hill. One has slipped and is being gvien a hand by the other. A vast panorama of an empty red plain is spread out behind them. But, just in the right corner is a mound of rubble--or is it. there are ancient seams in the closely-fitted rock wall....)
My take is that NASA needs to jump in with both feet to work the Boeing poster element a bit harder. They need to stop taking the safest, most boring approach (those flat empty plains are REALLY boring). The next landers ought to head for the Valley Marinaris, or the ice cliffs of the North Pole, or the slopes of Olympus Mons. WE the people want to see steep walls, caves, crevasses, all the striking features we see from the air, but never on the ground. By far the most interesting craft I can imagine would be a maneuverable derigible that could skim the surface and bring back hours and hours of low-altitude aerial video, preferabley in 3-D (steroscopic--not perspective 2-D). If the camera lenses were several feet apart, one could get thrilling stereopsis--the sense in the brain of visual plasticity--and perhaps rekindle in the general public the urge to send someone who could stop and check out that shadowed grotto, that hidden gulch, that tantalizingly rectilinear rock formation.
<<1) Earth and Mars were similar about 3.5 bya - in terms of air, water, temperature.
2) Life existed on Earth 3.5 bya.
3) Earth and Mars have never been quarantined from each other because of impact transfer of crustal material. (More impacts back then.)
4) It follows that life existed on Mars 3.5 bya.
...>>
Not true.
1. Mars is so small, it's interior would have had a molten metal core for only the shortest time period.
1A. Being farther away, it has less sun-warming.
1b. with the sun 30% colder then than now, it was even colder still on the surface than now.
2. With its molten core cooling down, it lost its magnetic field.
3. with no magnetic field, no van Allen belt was there to shield the planet from deadly cosmic rays, which then sterilized any surface life, if there ever was any.
4.with such cold, water vapor never got going to provide a heat shield so that the surface could warm up.
QED, Mars was never warm, is now the warmest it has ever been, but has the first several inches of its surface sterilized. Thus, any creepy-crawlies must be underground, if they ever arose, and extremophiles in the extreme--i.e., one celled cretures at best. Not good eating.
If you want a lot of oxygen in a small volume, consider LOX--liquid oxygen, which would be lot easier to keep liquid on Mars than on Earth (because it must be kept very cold).
Rebreathers are essential which means CO2 scrubbing, now done with highly effective lithium hydroxide.
Of course you also use chemical oxygen--postassium superoxide--KO3 as is used in mine rescue units. See velocitypress.com under "closed-circuit oxygen" for such a system used on Mt. Everest.
And, speaking of chemical oxygen, maybe the surface of Mars consists of highly reactive oxygen bearing minerals--the Viking exerimetns sure seemed to suggest that--in which case we need only scoop it up and breathe moisture on it to release copious amounts of oxygen.
<<What I don't understand, except when I have my conspiracy hat on, is why the "establishment" has so religiously shunned the evidence for life on Mars. It is remarkable to me that they have abandoned the principle of Occam's razor in this case, preferring to conjure up all sorts of exotic Martian soil chemistry (none of which anyone has been able to experimentally duplicate in 25 years of trying) rather than consider the obvious! >>
Ha! "Shunned evidence" is a good one. NASA has steadfastly claimed that everyone of its "this is even better than the last one" photos proves that Mars once had oceans of surface water, hence the layer they see all over the place.
But if you read the articles to the end, somewhere in the fine print, near the end of the page, might be a mini-disclaimer, something along the lines of: "and of course the layer might also be the result of wind transport of material."
What is so remarkable about this faith-driven science is that the only thing we do have positive proof of is wind-driven dust being carried everywhere on the planet. It even collects on the rovers, and then get blown off. Take a couple of billion years of wind-driven dust accretions, and pretty soon you get layers that, when they get deeper and deeper, are compressed into rock.
What I have not heard a single pro-lifer to have addressed is that in the early years of Mar's existence, when it supposedly still had an atmosphere (how anyone would know that is also not explained), the sun was about 30% less bright. Thus, in the early years, Mars would have been even colder than it is now. Indeed, Mars is suffering from massive global warming right now, and even so it's too darned cold for any life to evolve.
<<One general principle about 'life' in any form: If it ever existed, it is difficult to eliminate completely and totally. Assuming there was once life on Mars, to say that conditions have completely eliminated all remaining life is very unlikely. Life in itself is extremely adaptable, once it gains a foothold, and likely impossible to totally eradicate. >>
Yes, but that doesn't get us anywhere. Microbial life is probably ubiquitous in the galaxy. the problem is how to get multi-celled life and then plant and animal life--that is the extremely difficult process that probably never got started on Mars.
<Odds are that if life evolved here, that in the great vastness of the universe life evolve somewhere else as well.
But what are those odds exactly?
does 1 out of 10 suns hold a planet with life?
1 out of 1,000,000?
1 out of 10^100?
Thats why the search for life on mars is so essential.
If life independantly evolved on mars, then we can expect the universe to be filled to the brim with life. We can begin to speculate that life is not an oddity, or some fluke, but a natural and common progression across the universe.
>>
The above statistical method of wishing senient life into existance is completely baseless. Yet the results are so deliciously fecund, that all the BEM hopefuls (i.e., most astronomers) seize it with gusto--and carefully never subject it to any intellectual examination.
The only way to estimate the extent of life elsewhere is to describe how life arose on Earth, and see what the necessary series of events were that gave rise to "life." Then find planets that offer a similar route.
One note: Let's agree not to confuse the term "life" when we mean microbial "life," (to maximize its presence in the universe) and animal life, when we mean sentient (or at least precursors to sentient) life. The former is everywhere, the latter probably extremely rare.
When that sensible method is followed, the entire Drake equation goes out the window--as being not applicable to the question. And when we do examine the tortuous path of the development of animal life on Earth--how it required an anerobic beginning, switching over to oxygen based, the necessary types of other planets required for Earth to sustain this development, the necessity of an unusually large moon (to stabilize the seasons), etc., etc.--we see that the "statistics"of these new requierments make the likelihood of animal life on other planets vanishingly small--no matter how many billions of planets circle billions of suns.
So sorry!
Posted: Thu Jun 02, 2005 6:11 pm Post subject:
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<<Earth microbes may survive on Mars
Quote:
The team found that dormant spores of the bacterium had mostly died after five minutes of Martian UV exposure.
However, the bacteria were able to stay alive if they were shielded by just 1 millimetre of soil during the tests, which ran for up to 24 hours. >>
The whole issue of microbes on Mars or anywhere else in the galaxy is really moot. Microbial life is probably everywhere in the galaxy. They are incredibly hardy, able to exist under water at greater than boiling water temperatures, etc. The cosmic issue is, what happens next? Darwin's magic wand does not work until the conditions for life are very narrowly controlled. Thus, if you think (as all astronomers assume) that microbes + one billion years = animal life, you are very badly mistaken.
I am re-reading "Rare Earth: Why complex life is rare in the universe" by Ward & Brownlee. This book should really be required reading by everyone on this forum. It points out the extremely tortuous route the creation of animal life took on Earth, guided along by an incredible series of accidents that are so unlikely to have occurred in just the sequence needed, that the Drake Equation (and Carl Sagan's million sentient civilizations in our galaxy) goes right out the widow.
This series of coincidenes is so incredible, it might even resusitate the religious arguement--although to be credible, it would have to be made by an atheist.
Even if you restarted the development of life on Earth with the exact same conditions, you would end up with very different species. This is because the mutations that drive evolution are random. Thus humans would almost certainly not develop even on a planet witht he exact same conditions as Earth. And alien planets will be very different. Thus aliens will be very different.
Wrong. Random gnetic mutations are all tiny--and either help, hurt or are neutral in helping the species survive. Because the randomness is so huge (millions of random events) it tends to even out and let the advantageous mutations survive. At the end of the million years or so of homo erectus, this random mutation has so finely honed the surviving racial variations, that we are still heading toward a single race, with intelligence now playing astronger role than ever--our survuval needs having been seen after.
However, technology is beginning to interfere with Darwin by letting defective adaptations survive. Look at eyeglasses, which mean that babies born with poor vision can get along just fine--instead of dying out when they can't hunt because they can't see the game. Many genetic defects that would result in an early death, now stave off early death--and let that person procreate to creat other defective types who Darwin would have eleiminated naturally.
But, just when two completely separate teams build an aircraft , and--givenexactly the same requrements (range, load, etc.) will--if they are perfect engineers--build the same craft--because their is only one optimum solution given the reqwuirements and the laws of physics--so, too will sentient aliens tend tolook just like us IF their planet is just like ours.
If you don;t believe this, then you also don't believe in Darwin.
<<After the Mars moon was destroyed, there was not enough opposing gravity to keep the planet's molten core spinning. This eventually stopped the Mars core which failed to generate internal heat, causing too much of a temperature flux to sustain its warm atmosphere. >>
It's not the heat that disapated when Mars' theorized larger moon was eliminated, but the magnetic field. The molten iron core on Earth is churned by our very large moon, creating the magnetic field that creates the van Allen belt--which shields us from deadly cosmic rays. If we lost our moon, this churning would cease, the magnetic field would stop, the van Allen belt would disappear, and our planet would be cleansed of life by the influx of deadly cosmic radiation.
Details of a new study from UC Davies
Cracks and fins in the sand in an American desert look very similar to features seen on Mars and may indicate the recent presence of water at the surface
Well, yes, another one of the scores (hundreds?) of hints of hope that Mars afficionados cast out every couple of weeks to continue to try and drum up support for a manned mission.
I want a manned mission as much as the next guy, but I dont need water hype to sustain my interest.
Here's what we'll eventually find on Mars: Several feet under ground microbes and fossiles of microbes will be found--and nothing more complicated. And they'll essentially be variations of what has been found on Earth--because they probably all came from the same place--from comets that seem to seed the solar system and, probably, the rest of the galaxy. Only on earth (in this galaxy) have the microbes taken root and had enough time and climatic stability to evolve into complex animals
""The whole northern hemisphere of Mars is several kilometers lower than the Southern hemisphere - i.e. the northern hemisphere is indeed GIANT impact crater. The size of the impactor ( the maximum one ) could be easily estimated via using th Impact simulator or via calculating the gravitational binding energy of Mars. Serious hit. Caused by other protoplanet merging in. Moon size? The focil bulging of the southern hemisphere is pretty obvious to be result of the hit recoil...The other major hit, you see is the Helas baisin - much smaller body. NOt planemo, perhaps 200-300 km wide, hitting under big angle -- the planetary forensics could see the recoil effect -- the Tharsis bulge... ALL these hits occured when Mars formed, the same way as the case with Earth-Moon or Pluto-CHaron, or the stripping of Mercury, by hit and run blow...""
The problem here is that IF that were true, then it would have happend long before any life occurred. Or, giving you the benefit of the doubt, life had occurred, but in any case would have been snuffed out by such an impact--as it was on Earth several times.
The net-net: Other than microbial life--which seems to be everywhere, Mars never had a stable, life-friendly environment (that Earth did--thanks in large part to its very large moon) long enough for anything interesting to evolve.
""Granted Mars is a lot colder but the design is one that is inflated to shape and has a flexable solar cell build in. ""
You could as well consider the hyperbaric sack that is used on
Everest to reat High Altitude Pulminary Oedema?
""But my question was about near-to-room temperature phases of liquid or supercritical CO2 (in order to be compatible with earthly proteins and life)? Can you point me something about this?""
No, but I can remind you that supercritical CO2 is used to dissolve the caffein out of coffee beans to make decafe. It's called "the Swiss water process."
""Why does only a tiny speck in a perpetually expanding Universe called Earth merit life on it ? ""
A question that is beautifully answered by the book: "Rare Earth: why complex life is uncommon in the universe," by Peter Ward & Donald Brownlee.
[http://www.amazon.com/gp/product/customer-reviews/0387952896/ref=cm_cr_dp_pt/104-3912609-6948728?%5Fencoding=UTF8&n=283155&s=books ]
Could such a lake persist on the surface, alternately freezing and thawing, with surface evaporation being replaced by underground seepage of water into the lake basin?
It could. NASA used to claim it was impossible. Now they have had to change their tune.
Or maybe they knew it all along, but this is just another small step in the conditioning process we are being put through.
The conspiracy mentality needs to make up its mind. First it is a NASA conspiracy to push for the possibility of water at every opportunity (this was the current state of affairs) to justify a manned mission; now, with the above claim, it is just the opposite. Reminds me of the Jewish mother, seeing her son come down the stairs wearing one of the two new neckties she gave him for his birthday. "What?" she exclaimed. "You didn't like the other one?"
""Liquid water and life on Mars
http://www.biospherics.com/mars/spie2/spie98.htm""
This paper Almir noted is very interesting. But it is dated 1998. Has anything further been one to confirm of deny the likelihood of micron-thin layers of liquid water on Mars?
I guess the reason there are so many views and so few comments--this being the only one--is that everyone knows that this type of "photoanalysis" is the work of a person with a great deal of imagination but only a very weak grasp on reality.
""As far as the scrubber, the crude ones used on early submarines would probably be fine for the sort of short term stuff we're talking about. They used two chemicals, both of which I forget, one to remove moisture, and the other to remove CO2. You could have a small one rigged up with a fan and a couple batteries, no problem. ""
You mean potassium superoxide--KO2--as used in mines as emergency oxygen systems, and by me on Mt. Everest as a rebreather for sleeping and climbing. (see: http://www.velocitypress.com/pages/closedcircuit.php )
The reaction is started by a clorate candle which produces instant oxygen for a few minutes, long enough for the moisture from your breath to energize the KO2 reaction. KO2 generates oxygen and absorbes CO2--so you can "rebreathe" oxygen that already went in and out of your lungs, but wasn't absorbed.
However, the idea of backpacking oin Mars seems farfetched. You would never want to be far from a safe-hole, and that would seem to be a vehicle with a pressurized cabin for driving as much as possible, radios, water, food, etc., and --most important--over at least a little protection against cosmic rays.
""If there is any life on Mars, it's unlikely to be at the surface. The first humans to go will have had plenty of time to decide how to protect it, (not to mention the 30+ years between now and their arrival) ""
No chance of that. The Martian surface has been throughly sterilized by UV radiation from the sun unfiltered by any significant atmosphere, and sterilized to a depth of at least several inches by cosmic rays from the sun, undeflected by a magnetic field.
Any "life" to be found on Mars will be deep underground, and will be microbial, not plant or animal.
(The lack of a cosmic-ray shielding van Allen belt will make terraforming Mars very difficult.)
"Houston, Texas (SPX) Feb 8, 2006
New examinations of a Martian meteorite found nearly a century ago have strengthened the possibility that the red planet once harbored life.
"I don’t understand the sample completely just yet, but it’s exciting," research team member Kathie Thomas-Keprta told SpaceDaily.com.
http://www.marsdaily.com/reports/New_Vi … _Mars.html
This exciting story is expertly recounted in the book "The Rock from Mars: a detective story on two planets," by Kathy Sawyer. http://www.amazon.com/gp/product/140006 … e&n=283155
Read this book for the fascinating scientific analysis undertaken, and how scientists had to work out new techiques for measuring and evaluating what they thought they had discovered--fossiles of Martian bacteria.
That's the first half of the book. The second half describes the politics of what happens when these volatile discovery claims are made. Whew--talking about the tapiocca hitting the fan!