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NASA Probes Reveal Vast Stores of Martian Ice
John Faughnan writes: "The BBC reports that a British newspaper has leaked stunning news from the Mars Odyssey spacecraft. Vast amounts of water ice are present on mars, "[if it] were to melt it could cover the planet in an ocean at least 500 metres deep." Researchers thought it would take a year to detect any water ice below the martian surface, but the huge quantity meant that weeks of observation were sufficient. The BBC notes that "The Mars Polar Lander was to touch down in exactly the right spot in 1999 and would have undoubtedly detected the ice had it not malfunctioned on the way down." This discovery will change plans for upcoming probes and may lead to a manned mission within the next two decades. The official announcement was scheduled for this Thursday prior to several publications."
This is a serious step ahead for the feasibility of a terraforming project. I'm reading the Mars series from Kim stanley Robinson at the moment, this article is spot on!
If this probe detects ice in the first meter of soil from 60 degrees south to the pole, how could it find enough water to cover all of Mars to 500 meters? There must be assumptions not described here, or a math error.
This makes the colonization of Mars possible. This makes Terraforming possible. This makes fuel manufacturing easier. This makes oxygen generation easier. IF NASA plays this right we could easily be there by 2020. I just wish the money and the will exsisted because we have the technology to do this now.
There is nothing inherently safe about liberty. That's why so many people died protecting it.
Hopefully a real manned mission will come out of this. We've set our sights to low in the past 30 years and allowed to many choice moments to pass. After we let the Pluto mission lose its chance to study an atmosphere I had lost all hope for Nasa.
We must make a manned mission to Mars, people may talk about cost and worry over what scientific results it would have. Ignore that; go to Mars because it is there.
Feminism is the radical notion that women are people.
I thought we always knew mars had quite a bit of ice at the poles, but the fact that there is now enough to cover the whole planet in water is very interesting, i doubt the *whole* planet was ever covered in water though, because if so the whole surface would end up being ice right?
"The United States has no right, no desire, and no intention to impose our form of government on anyone else." - Bush 05
They don't have to take water with them. It costs $10,000/pound to put something in orbit. One gallon of water will cost about $80k to put up there. So, there's a weight and cost savings using local water. Plus, they should be able to use the water to generate hydrogen and oxygen, for fuel and survival.
Napster-to-go says "Fill and refill your compatible MP3 player", which is a lie. It's not MP3. It's WMA with DRM.
I don't quite understand how the discovery of ice on mars would make manned missions any more possible. Don't they take water with them on missions anyway?
If its already there, it means that you don't have to bring it with you (or at least not as much).
Water can be used in the production of oxygen, and also fuel (after you break down into Hydrogen and Oxygen). These things require a LOT of water... much more than we could possibly hope to bring with us.
Discovery of water also means that the chances of finding life (or at least sign of primative life that once existed there) are much, much greater.
Easily acessible water ice is critical to making manned missions much easier. It's terrific for producing potable water (im assuming they'll filter it!), and can be broken down (via electrolysis?) into component Hydrogen (rocket fuel) and Oxygen (useful stuff). Zubrin's gonna have a field day with this, he's outlined an excellent;y thought out mission plan that hinges on ice below the surface. Now if we can just get those fresnel lenses or mirrors in orbit a la KS Robinson.......
Think your 2.2 ghz p4 is impressive? I've got chloroform molecules and an nmr machine!!! Mwahahahahahahaha!!!
Assuming that you're correct physically--that, is, that water wouldn't be a problem for the duration of a manned mission to Mars--you're still missing a big aspect psychologically. It's a lot harder to say to the public, "Oh, look, here's this dead dry planet which could never sustain Earth colonies. Let's go waste valuable resources on a manned mission." (Not that I think it would be a waste even if it were dry, but you know how some people think).
The existence of water captures the imagination. It makes us think that the Red Planet could someday be blue, or even green (Kim Stanley Robinson, anyone?) It makes it so much easier to sell the public on the mission, because the possibilities have increased.
I hope that the fact that Mars has that much water really will help overcome a lot of psychological barriers which had previously been in place.
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Water is the single most important thing we could find on a planet. Our biology is carbon and water based, we need water for all biological processes. Ecologically, large quantities of water act as a temperature regulator for the planet - water is only found in liquid form over a very narrow range of temperatures, but in that form it is an especially good solvent, lubricant and transport mechanism. Chemically, water consists of hydrogen (pre-cursor to most chemical fuels, and one day, in the form of deuterium also to controlled fusion) and oxygen (also a fuel, and necessary for life!).
Remember, moving even a kilogram of mass out of the earth's gravitational field is very costly (in fuel and resource terms), so finding such an important resource "in place" is very exciting news, and could significantly accelerate mankind's expansion through the solar system and beyond.
Dan
The care needs to be taken in the other direction. Water means that Earth life can live there--for instance, bacteria of the Antarctic sort. If we want to know about Martian indigenous life, we need to not inadvertently release several hundred species of microbes on the planet, some of which might take hold and crowd out any existing forms.
Even if they didn't adapt and live, sorting out their chemical components from those of native forms would complicate research.
Sterilizing an entire spacecraft is no easy job in the first place, and it gets much more difficult when the contents include live human beings.
Has anyone actually looked at a Mars map? I'm running the latest version of the Mars Simulation Project, looking at the planet in topography mode.
This planet has altitudes ranging from approximately -8000 meters to +22000 meters, with two very distinctive zones: around -100 W, mostly on the southern hemisphere, there is a huge, +5000 meters continent; the northern hemisphere is between -5000 and 0 meters; and there is a very impressive hole centered at 70 E and 40 S, between -7000 and -5000 meters, sourrounded by a 0 to 5000 meters zone - what happened there? A huge spacial hit?
Anyway, saying Mars would be covered by 500 meters of water is completely meaningless. I guess they took the quantity of water and divided it by the surface of Mars. They mostly want to impress people, I guess, but I for one would be more impressed if someone came with a new Mars map showing the areas where the "sea" would be once the ice was melted. There is an illustration there, but of course it doesn't take into account the "real" quantity of ice/water.
Yeah, they might use some of that commie Linux software! 8)
-l
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In a related story, NASA has announced that it will abandon its space exploration effort in favor of running a ski lodge catering to exclusive, high-income customers, like "P. Diddy". An unnamed source close to NASA has said that "We need to turn a profit, you know? Those rockets don't run on hydrogen, they run on good ol' American greenbacks! Like the ones P. Diddy has! He loves to ski, did you know that? He's big into everything NASA is into."
"P. Diddy" declined comment, sighting his long history of producing music videos with fish-eye lenses, shiny space suits, and unmarked black helicopters.
Cheers,
Bowie
Bowie J. Poag
Of course, if life is actually found there, the chances of them sending a manned mission anytime soon are zero. :/
-l
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The problem isn't NASA's will to do it. It's funding and the laws of physics. The laws of physics make it extremely difficult to protect astronauts from radiation well enough to keep them healthy on such a trip, which would involve several years coasting in interplanetary space.People also don't realize how debilitating long periods in zero-g are. They often have to carry astronauts away in wheelchairs when they come back from a long period in orbit.
This makes a lot more sense. There's really nothing of scientific value that people could do that a sample return mission couldn't. Sending people into space has never been a good way of doing science; that's why they never have to compete for funding in peer review, because they'd lose.
We could bring back a sample within five years if we wanted to. If it had bacteria in it, it would be one of the most momentous scientific discoveries since the age of Galileo and Newton.
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Building a vehicle that would send a colony to Mars is not easy task, from what I've read NASA would have to build something or at least assemble parts in orbit. Unfortunately Joe Public has a major problem with nuclear -- he is scared shitless that if we have something nuclear circling the globe it will crash on Earth spreading radiation.
This is the point of my argument -- build a nuclear propelled rocket but assemble it in Moon's orbit which would provide safety in case of problems. I don't think anyone would complain if we accidentaly nuke the Moon since it a dead rock anyway. At the same time a base on the Moon would make for a good location for the people working on the construction of the rocket. Especially if US can put a base on the Moon before Chinese get there.
This is great news if there is water on Mars but i believe one of the major stumbling blocks on a manned mission to Mars and sustaining him isn't so much water
but getting people there alive.
Astronauts just on the journey (180 days each way + 550 days for return journey planetary alignment) would be exposed to lethal doses of radiation meaning when they got to Mars they would already be too ill and poisoned to be of any use to science let alone come home, i don't really feel that comfortable in sending (volunteers) to die a horrible slow death from radiation sickness under the guise of "research"
NASA have did do some research in 1998 on using dirt for shielding on any base but this doesnt answer the journey time radiation exposure problem
I think we forget in our own insignificance that the ISS and the shuttle fly close enough to the Earth's magnetic field and our atmostphere to be protected from the worst effects of our Sun (radiation,flares,magnetic bursts,uv, etc) but once we leave for Mars we will be exposed to the Suns full destructivness and we still havent developed protective materials/shields (short of 6ft thick lead) that will protect us long enough not to kill us in the 915 day exposure of such a mission.
I am still suprised that we think we can send people there after water when so far all we have sent is a glorified "remote control car" instead of an advanced humanoid type robots like this into space
Nitrogen in the air isn't consumed by humans, so the same volume of nitrogen brought from home could be used forever (as long as it doesn't leak, of course) with the oxygen being replinished by the water and the co2 being filtered out. I don't know if it would work in practice, tho.
And yeah, Mars' atmosphere is a tiny fraction of the pressure of Earth's, so you'd have to have space suits or a pressurized building or something to live.
--
Benjamin Coates
As explained here, earth bacteria survived on the moon for 2 years.
IIRC, they sterilize some space probes by blasting them with radiation before launch.
I was happy ina kind of boyish school kid kind of way about reading this. I don't really think it makes that much difference in reality to the actual *need* or feasability for a permanent manned Mars base, because the Mars northern polar cap always had water ice (or was it the southern one? in any case one did) and a manned base would have had to melt the stuff anyway.
The long term effect of this is that perhaps our descendants will be able to terraform the planet as envisaged by Kim Stanley Robinson and this is the kind of news piece that NASA needs to get public support for a Martian base, although, as I said above, in reality it doesn't change things that much.
To the guy who warned about Radiation poisoning from solar storms on the trip to Mars. Ship designers have been thinking about that one for a long time and this is where the concept of a storm cell on board a ship comes from - a thick walled cell whose walls are basically water tanks to absorb the radiation i.e. ionised particles.
One other thing that should be noted is that if the water is ever leaked to the surface, along with an increase in heat via CO2 being pumped into the atmosphee, then there will probably be a reduction in the amount of dust in the atmosphere, as the iron binds to water droplets. This would modify the atmospheric conditions and probably reduce the number of violent storms. Also, a humid atmosphere would probably also make it more favourable to life, if there isn't any already there.
Without water it would be much more difficult to teraform the planet.
This is unresearched, but I believe that it is a probable scenario, based on the knowledge I have.
Jumpstart the tartan drive.
It would solve the biggest problem, though. Heat is one of the easiest things to produce (solar power, nuclear plants, even heat from the planet's core). And once you have an atmosphere going, heat becomes much easier to conserve.
Creating a functional, stable atmosphere is easier said than done, though. We don't even quite understand how the Earth's atmosphere works (nor, according to a recent Slashdot poll, how the atmosphere of a romantic evening works).
And as to there being enough water to cover the entire planet in an ocean 1/2 Km deep, I doubt it. They're probably assuming the water will not be absorbed by the soil. I have no idea how deep martian bedrock is, but the surface is quite "sandy".
RMN
~~~
TWW
"Encyclopedia" is to "Wikipedia" what "Library" is to "Some people at a bus stop"
Terraforming is a neat thought experiment.. but seriously. How arrogant are we to think we can take a place like Mars and make it habitable for humans when we can't even get our OWN planet under control? We are quickly decimating the earth and looking for a new planet to use.. so we can what, destroy it too?
Arranging the tanks and compartments that carry such stuff to provide a solar storm safety shelter in the center of your "tin can" is a trivial design exercise. A meter or two of water between you and the radiation is pretty much all you need. The ambient radiation is a problem, although only in percentage terms (it slightly increases your chance of getting cancer sometime later in your life). The point has been made that you could recruit the crew from smokers; they couldn't smoke on the mission; and you would actually decrease their chance of getting cancer during their lives by sending them to Mars!
Many, many design studies have been done utilising exactly the design I mentioned above, and it works. Read about it in this book or at this website.
Somebody or something sure is rubbing it in.
"We found out that you would have discovered a cure for cancer if you hadn't been using a MS OS."
Table-ized A.I.
Say you're right, worst case scenario, and we screw up when terraforming mars. Who cares? There's no way we're going to make it LESS habitable, and we can just bring our people home. As for any martian microbes that may buy it - well, I'll shed a single tear for them, I guess.
I'm the stranger...posting to
So would the water be saline, like our oceans? Or would it all be fresh water?
--
Some weasel took the cork out of my lunch.
I recall reading an article about one of the early space tester guys who went up 100,000 feet or so in a balloon and then sky dived back (setting the world's record for that as well). Apparently he had a leak in one of his gloves and his hand swelled up a great deal at the height.
-
It looks like the biggest roadblock to Mars colonization will not be air, water, or shelter, but microdust particles.
Simply put, Mars has a very active atmosphere, which is a big planetary grinder, for lack of a better word. Some of the dust on Mars is so fine as a result of the atmospheric dynamics that it poses a danger to humans.
How? Even though colonists would not breathe Martian air directly, the very small dust particles there will get into pressure suits and living quarters. Essentially, there is a danger that people would be breathing particulates and getting a Martian version of black lung.
We don't know the extent to which this issue poses a danger to settlers, but it is a very real one. Add to that the harsh conditions, the dangers of dust storms, meteor showers, and unknowns we can't forsee, colonization of Mars will be very difficult indeed.
Indeed. Basically, I believe that "terraforming" a planet won't really be possible until we have some form of self-replicating/assembling machine. If we had that, I suppose we wouldn't be that far off from being able to build a soletta to reflect additional sunlight onto the planet. For now, however, this will all have to realistically remain science fiction.
C//
Water can be used in the production of oxygen, and also fuel (after you break down into Hydrogen and Oxygen).
Molecular hydrogen might be a nice commodity on a planet with an oxidizing atmosphere like Earth, but on Mars, it's a by-product. What are you going to do you do with it? Burn it in a fuel cell or an internal combustion engine with the liberated oxygen to generate electricity? But you have to use a little nuclear reactor to electrolyze the water in the first place. Why don't you just use that for power instead? It's not like the combined electrolysis/recombination process will operate with 100% efficiency.
Damn, wish they had figured out that there was that much water up there 20+ years ago. Between the Soviets and the US we could have had ourselves one hell of a space race to the red planet.
As things currently stand, the Chinese will probably get there unopposed, while the US tries to get funding and political support from its international partners, and the Russians sit around with perfectly good hardware, waiting for someone to hire them.
Until fusion comes along, we'll just have to make do with fission reactors. Bring enough transuranics to fuel your reactor, maybe establish a breeder when you get into lunar orbit to supply future reactors. With a nuclear reactor, you can power a vasmir-type rocket, with hydrogen as ionizable reaction mass, or if you want to be crude, you can supply water directly to the reactor and expell the mass as radioactive steam. Once you get to Mars, deploy some of your spare fuel rods as another reactor on the surface for your chemical fuel/oxygen plant.
The nice thing about having so much power available is that you can start thinking about using magnetic shielding against ionizing radiation, an important consideration for missions outside of Earth's magnetic field.
I still say the first mission using a nuclear engine should be an unmanned shopping trip to the asteroid belt to pick up a few choice chunks of ice and metal to park at a lagrange point for use in resupplying and building. Then we push on to the Moon, and then, Mars. The key is getting a reactor outside of Earth's gravity well, once that's done, it's all about gathering raw source materials for processing and building. Heavy industries in space...
Check out some of NASA's planned (well, studied anyway) missions.
Nova had something on once about how mold spores travel, they are in the upper atmosphere and have even been found in space! The point was they are still alive after all that, so a little ice, UV radiation and a near vacuum wouldn't hurt them on Mars.
Pure Vacumn + Unfiltered UV Light + No Water + Heat/Cold Extremes = No Surviving Bacteria. What else are you going to do, swab the thing with alcohol?
I learned the same in school. But our school knowledge is outdated.
Mir was eaten by funghi. A mojor reason why it was gave up. They lived everywhere, even in teh vacuum parts of the Mir.
Bilologists made tests: putting bacterias into vacuum. Most dried out and could be revived with warer and nice conditions.
A lot of bacteria produce "spores" (right word?) those can survive vacuum and radiaton for decades if not centuries.
There are biologiests, more and more now, believing live on earth was seeded by comets containing bacteria live(or simpler live forms).
Alcohol is an other issue, it destroyes the outer membran of the bacteria. Vacuum mainly causes them to dry. Dried they are tiny and hard to kill by radiation.
angel'o'sphere
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
This supports one of the major theories of Martian water and what the hell happened to it. On Earth there's a process the planet has to cycle carbon dioxide into and out of the atmosphere. This is entirely dependent plate tectonics however. The theory is that Mars was warm and wet a billion years before Earth was but because it cooled faster than Earth because it was smaller its plate tectonics ceased. When that happened the CO2 process couldn't continue and the oceans began to freeze into the ground. It would be really cool if this discovery promoted more exploration on Mars. Having an ice boring probe discover some form of life would be pretty interesting. I wouldn't expect anything to be alive currently because its been many billions of years since water was a liquid on Mars. Even the deepest ice on Antarctica isn't older than a few millions of years.
I'm a loner Dottie, a Rebel.
Oxygen is poisonous.
... so thats not poisonous?
Try to breath in a 100% oxygen atmosphere.
Probably it even burns your lunges
Probably just a wording matter. Reduce pressure of the oxygen to about a 5th of standard presure, still enough oxygen to live from, not enough to burn you, but enough to poison you.
angel'o'sphere
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Sure, to provide electrical power to the base, use the reactor.
But fuel cells can power vehicles and mobile instrumentation, liquid O2/H2 can power return vehicles, and H2 can be used for all sorts of other things (since you've gone to all this trouble producing an oxidizing agent, might as well use the reducing agent, too). It can reduce carbon dioxide (Sabatier process), producing O2 and CH4. If you can find some N2 (there's a bit in the atmosphere -- maybe you could distill it), you can make ammonia (good old Haber process), and then you're on the way to fertilizer (for your houseplants), explosives (for your ground war with the Earth forces[1]), and smelly cleaning solutions (for your linoleum floors). And, who knows, by the time we're worrying about all this excess H2, maybe we'll be good at fusion, which would be nice because all of the stuff above requires energy, and energy is the real problem.
In any case, the question isn't "what can we do with molecular hydrogen?" but "what can't we do with molecular hydrogen?"
Another question is, what are you doing with all the molecular oxygen that you're producing so much molecular hydrogen that you don't know what to do with it?
[1] A bit of irony -- Germany was greatly aided in her efforts during the First World War by a BASF plant producing ammonia using molecular hydrogen obtained from...wait for it...electrolysis!
Well, I might make typos, but grammar errors?
I doubt there are many, especially in those short paragraphs.
angel'o'sphere
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Blockquote:
Equate average molecular thermal energy (3/2)kT with kinetic energy (1/2)mv^2 and you get v=sqrt(3kT/m). Where k is Boltzmann constant (1.38e-23 J/K), T is in Kelvin and m in kg.
Now O_2 has mass 2( 2.66e-26 kg) = 5.3e-26 kg.
And H_2 has mass 2( 1.67e-27 kg) = 3.3e-27 kg.
Which comes from atmoic weight / Avogadro's 6.022e23 = grams/molecule.
Say room temperature is 79F, 22C, 295K then O_2 is zipping around at 480m/s or 0.48 km/s (about 1000 miles an hour), similarly the average H_2 molecule is going at 1.9 km/s.
The escape velocity for Earth is 11.2 km/s and for Mars 5.0 km/s.
So at first glance earth can hold onto the average O_2 and H_2. Which is clearly not the case (Earth!=Gas giant). The rule of thumb is if the average molecular speed is greater than 6 times the escape velocity then it stays, otherwise it leaves.
So 6*O_2 speed is 2.88 km/s, 6*H_2 speed is 11.4 km/s. So H_2 leaves earth's 11.2 km/s escape velocity, and O_2 is still well within Mars's 5.0km/s.
If you use bc to check the math, set "scale=30" to avoid div zero.
Yeah, put a bunch of recent ex-smokers in a tin can, and lock it shut for 3 years.
Evil martians won't stand a chance against psycho Terran nicotine addicts.
-Styopa
Doesn't this radically increase the liklihood of life being found on Mars?
I mean, that's a heck of a lot of ice, and we've got boatloads of bacteria that can/do survive in the Antarctic. Why not on Mars?
-Styopa
Try google with "mir mold" for more info. They had mold growing on the outside as well as inside.
Anarchists never rule
Worked for Australia.
Posts like this one are why I still read slashdot. The good news is that since it can hold Oxygen gas, it can also hold an ozone. So, given enough time, people can not only breathe, but they can go outside in the daylight.
Yes Oxygen is constantly 'oxidizing' our cells. It is what gives us life and what kills us as well... oxygen is what shortens those telomeres that tell a cell when to die which is good or else we would all turn in to big cancers.
There's obviously more to it than this, so lok it up. To summarize though, pure oxygen is not conducive to a full life span.
A fool throws a stone into a well and a thousand sages can not remove it.
Well -- falling from an airplane and landing on your head isn't very healthy, either, but I don't think that you could call it poisonous. Just because it's bad for you doesn't make it "poison". So yeah, I wouldn't call oxygen poisonous.
How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
Hey! then you can burn the hydrogen and oxygen to produce more water, and then use that to generate hydrogen and oxygen again. Sounds like a plan, Stan.
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Second, which is not so obvious. We only need to send enough oxygen for the trip there. Why? Well, ice is water, water is H2O
2 parts Hydrogen, 1 part Oxygen.
Umm.. why bother to make oxygen from water when the martian atmosphere is made of CO2?
1 part Carbon, 2 parts Oxygen.
Pumping the atmosphere is much easier than mining ice.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
It would be interesting to correlate this map with an infrared thermal scan to detect geological hot spots - you might find underground liquid water that can be pumped instead of mined.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
This is absolutely wonderful news. Now we need to get some models of whether orbital mirrors on the poles can create an atmosphere that will keep your skin together, and if so then how soon!
But before that - core samples at the poles! There's a lot of easy to access history and maybe some organics we should know about in there.
In the next 30 years we are going to have either an incredibly well policed and defanged world, or an awful lot of horrible politically motivated NCB disasters. And we don't have anywhere yet for the race to survive if we should make a mess with energy or nanotech research.
Best thing going for Mars is, nobody's there yet that we know of, and anyone who goes will be likely be too busy playing the only game there is -- think of a new environment and what the survival traits will be. Time to fund nuclear rockets, breakthrough propulsion, and other things fanatics don't want to hear about.
Actually, wouldn't even frozen water potentially be a source of other dissolved gases. A scouting probe would probably be able to get the inert gases from mars athmosphere with a few years in advance.
But the real advantages of this will probably be in more unconvetional solutions.
Large amounts of water to farm seaweed and protein- no need for inert gases.
Efficient and easy-worked building material for under-surface colonies.
...in the end of "We Can Remember it for you Wholesale," also known as "Total Recall."
Eternal vigilance only works if you look in every direction.
Ah, thanx, I will take care of that in future :-)
...", but not "the Mons Olymp"?
:-/ In german its more or less the same rule, so I should be able to remember it and to adapt my writing to it.
So you write "the possibility of
To bad, I have missed that in school
Thanx for the hint!
angel'o'sphere
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Sorry, just being a pain in the arse.
Breathing 100% oxygen at standard atmospheric pressure is lethal. Breathing pure O2 at 2.6 PSI is just peachy. As I was taught, what really matters is the partial pressure of a gas. At standard sea-level conditions, (14.7 PSI, 101.3 kPa), the air you breath is about 18% O2. That makes the oxygen partial pressure .18 * 14.7 PSI = 2.6 PSI. As long as the partial pressure of O2 doesn't go over that figure by too much, regardless of the absolute pressure, you're OK.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.