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Coffee House => Coffee House Boards => CH / Science and Technology => Topic started by: blobrana on March 02, 2004, 12:54:46 AM

Title: Nasa is to reveal Mars water secrets...
Post by: blobrana on March 02, 2004, 12:54:46 AM
The US space agency's "Significant findings" about water on Mars will be announced  today in Washington DC.

I hope that by confirming the planet was a wet world like Earth some time in its geologic history, and that Mars retains significant amounts of water even today; they will establish that conditions were also suitable for life as well...

i`ve got a feeling that mars is crawling with underground lifeforms...er, like the earth...

  :-o
Title: Re: Nasa is to reveal Mars water secrets...
Post by: cecilia on March 02, 2004, 01:17:24 AM
"Warning, Dr Smith!!!"
"Warning!!!"
Title: Re: Nasa is to reveal Mars water secrets...
Post by: KennyR on March 02, 2004, 01:25:04 AM
Quote
Blobrana wrote:
i`ve got a feeling that mars is crawling with underground lifeforms...er, like the earth...


Well, they obviously don't use sunlight, or Mars would be green. So they would have to live off warmth and sulphides produced by volcanism. Trouble is, unlike Earth, Mars cooled out a long time ago. No more volcanism. So where would they get their energy from?
Title: Re: Nasa is to reveal Mars water secrets...
Post by: Speelgoedmannetje on March 02, 2004, 02:22:10 AM
@KennyR

Well, in the deepest parts of the sea here on earth, weren't there lifeforms based on sulphur (and so), other than well where we're based on?


so these probably work different.

Why HAS it to be green?
Title: Re: Nasa is to reveal Mars water secrets...
Post by: blobrana on March 02, 2004, 04:19:47 AM


Well,
Mars has a lot of sulfer...
i think that the one biggest problem with my theory is that (if life does exist underground due to the hostile surface) any life-forms, given enough time, would have adapted to surface conditions and we should be able to see them...

Unless they are recovering from some past planetary extinction event...

There have been recent discoveries of hydrogen peroxide on the surface, (it`s nasty stuff), and the climate has undergone through several `ice ages`, so perhaps life-forms have gone underground, and have a very slow metabolism...

I don`t think the probes have any instruments on-board to look for living life-forms (except the cameras)..

Hum,
So what`s the bet that nasa says they haven`t found any evidence of life...





Title: Re: Nasa is to reveal Mars water secrets...
Post by: bloodline on March 02, 2004, 10:40:04 AM
Quote

Speelgoedmannetje wrote:
@KennyR

Well, in the deepest parts of the sea here on earth, weren't there lifeforms based on sulphur (and so), other than well where we're based on?


so these probably work different.

Why HAS it to be green?


Bet even sulphur based organisms need a heat source! I agree with Kenny, without volcanic activity, life on Mars is unlikely :-(
Title: Re: Nasa is to reveal Mars water secrets...
Post by: bloodline on March 02, 2004, 10:42:42 AM
Quote

Speelgoedmannetje wrote:
@KennyR

Well, in the deepest parts of the sea here on earth, weren't there lifeforms based on sulphur (and so), other than well where we're based on?


so these probably work different.

Why HAS it to be green?


Bet even sulphur based organisms need a heat source! I agree with Kenny, without volcanic activity, life on Mars is unlikely :-(
Title: Re: Nasa is to reveal Mars water secrets...
Post by: bloodline on March 02, 2004, 10:45:04 AM
Quote

Speelgoedmannetje wrote:
@KennyR

Well, in the deepest parts of the sea here on earth, weren't there lifeforms based on sulphur (and so), other than well where we're based on?


so these probably work different.

Why HAS it to be green?


Bet even sulphur based organisms need a heat source! I agree with Kenny, without volcanic activity, life on Mars is unlikely :-(
Title: Re: Nasa is to reveal Mars water secrets...
Post by: bloodline on March 02, 2004, 10:46:47 AM
Quote

Speelgoedmannetje wrote:
@KennyR

Well, in the deepest parts of the sea here on earth, weren't there lifeforms based on sulphur (and so), other than well where we're based on?


so these probably work different.

Why HAS it to be green?


Bet even sulphur based organisms need a heat source! I agree with Kenny, without volcanic activity, life on Mars is unlikely :-(
Title: Re: Nasa is to reveal Mars water secrets...
Post by: bloodline on March 02, 2004, 10:56:50 AM
Quote

Speelgoedmannetje wrote:
@KennyR

Well, in the deepest parts of the sea here on earth, weren't there lifeforms based on sulphur (and so), other than well where we're based on?


so these probably work different.

Why HAS it to be green?


Bet even sulphur based organisms need a heat source! I agree with Kenny, without volcanic activity, life on Mars is unlikely :-(
Title: Re: Nasa is to reveal Mars water secrets...
Post by: bloodline on March 02, 2004, 11:05:14 AM
Quote

Speelgoedmannetje wrote:
@KennyR

Well, in the deepest parts of the sea here on earth, weren't there lifeforms based on sulphur (and so), other than well where we're based on?


so these probably work different.

Why HAS it to be green?


Bet even sulphur based organisms need a heat source! I agree with Kenny, without volcanic activity, life on Mars is unlikely :-(
Title: Re: Nasa is to reveal Mars water secrets...
Post by: bloodline on March 02, 2004, 11:26:05 AM
Quote

Speelgoedmannetje wrote:
@KennyR

Well, in the deepest parts of the sea here on earth, weren't there lifeforms based on sulphur (and so), other than well where we're based on?


so these probably work different.

Why HAS it to be green?


Bet even sulphur based organisms need a heat source! I agree with Kenny, without volcanic activity, life on Mars is unlikely :-(
Title: Re: Nasa is to reveal Mars water secrets...
Post by: blobrana on March 02, 2004, 11:32:01 AM
Well mars has a semi-molten core, and there are reasons to believe that there are deep volcanic activity still happening. It has even been suggested that a few of the viking images show volcanic steam venting...
Theres a nice image here:
http://mysite.freeserve.com/blobrana/cefoss.jpg (http://mysite.freeserve.com/blobrana/cefoss.jpg)
That shows the source of a water flow...the line of `dots` are probably a natural aquifer that is/was sitting above a thermal heat source...

The question is when the heat source cooled...(or if)...
And perhaps their metabolism has adapted, so as not to require an external heat source...Even at minus 120 degrees chemical reactions stall take place (slowly)...

UPDATE on Meeting:
NASA's associate administrator Ed Weiler accompanied by the mission's top geologist Professor Steve Squyres  will attend the press conference at 1900 GMT.


Visual inspection indicates that the region's spherules are made of different material than the matrix rock. The layered rock is tan, while the spherules are gray.
The bulk, or "matrix," of the rock, is composed of very thin layers. The spheres, or "spherules," embedded in the matrix, are about half a centimetre.
One theory about the  origin is that the spherules are "what geologists call concretions." Concretions form when water flows through a rock, carrying tiny bits of dissolved sediment along with it.
The sediment "precipitates around a nucleation site, and it grows these little spherical granules within the rock."

But then again it could have been the discovery of a jaw bone that swayed the balance: see `rock` near upper right , next to the skullcap...
http://marsrovers.jpl.nasa.gov/gallery/all/2/n/036/2N129563086EFF0361P1635R0M1.JPG (http://marsrovers.jpl.nasa.gov/gallery/all/2/n/036/2N129563086EFF0361P1635R0M1.JPG)
 :insane:
Title: Re: Nasa is to reveal Mars water secrets...
Post by: JaXanim on March 02, 2004, 01:42:24 PM
Heat, or more specifically, temperature is a relative parameter of life.

We like things around 20C. Organisms living around hot springs like it at 100C. Organisms around the deep oceanic black smokers are happy at 150C. Algal life has been found thriving hundreds of metres inside the Antarctic iceshelf. Not much heat there and certainly no light.

The fact is, life occupies every nook and cranny of the Earth, provided there is water. Whatever else these things need, they seem to find it. If there's water on Mars, life would not only be possible, but probable.

Cheers,

JaX
Title: Re: Nasa is to reveal Mars water secrets...
Post by: sumner7 on March 02, 2004, 01:45:19 PM
@blobrana

I like your new avatar a lot.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: KennyR on March 02, 2004, 02:07:16 PM
Quote
Speelgoedmannetje wrote:
Well, in the deepest parts of the sea here on earth, weren't there lifeforms based on sulphur (and so), other than well where we're based on?


so these probably work different.

Why HAS it to be green?


Nope, it's a matter of chemistry. At the temperature ranges where water could be used as a solvent for life (0-100C of course), green chlorophyll happens to be the most efficient chemical for photosynthesis. There are other kinds - brown, red...but these are a lot less efficient and are used by plants that don't have any other choice, like deep seaweeds. It's hard to imagine single-celled bacteria with brown or red chlorophyll being able to survive in the limited sunlight and low temperature Mars provides.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: Speelgoedmannetje on March 02, 2004, 02:12:11 PM
Quote
green chlorophyll happens to be the most efficient chemical for photosynthesis
How do you know that? Source? :-)
Title: Re: Nasa is to reveal Mars water secrets...
Post by: KennyR on March 02, 2004, 03:13:38 PM
Quote
green chlorophyll happens to be the most efficient chemical for photosynthesis

How do you know that? Source?


Look outside.

Evolution is a hard taskmaster. It always goes for the most efficient processes. Less efficient ones just die and disappear, except in places the more efficient ones don't work.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: Speelgoedmannetje on March 02, 2004, 03:20:20 PM
IF evolution 'found' a better way.

Nature is far far far from perfect y'know. And evolution is still going on.

And why should it be green on Mars? Maybe there's happening the same, but less/more efficient.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: redrumloa on March 02, 2004, 04:16:56 PM
Quote
Well, in the deepest parts of the sea here on earth, weren't there lifeforms based on sulphur (and so), other than well where we're based on?
\

Agreed. I am certainly no Mars expert, nor any other expert;-) But I think it is foolish for scientist to make blanket statements like "Life is only possible under X-condition". Finding life thriving in the deepest parts of the earth's oceans shook alot of things up:-)
Title: Re: Nasa is to reveal Mars water secrets...
Post by: KennyR on March 02, 2004, 05:09:30 PM
Quote
Speelgoedmannetje wrote:
F evolution 'found' a better way.

Nature is far far far from perfect y'know. And evolution is still going on.


It had about two billion years to perfect photosynthesis before animals started to appear. It's had plenty of time. There is nothing more efficient than blue-green chlorophyll, because if there was, it would be here.

Quote
And why should it be green on Mars? Maybe there's happening the same, but less/more efficient.


Then where is the oxygen by-product?
Title: Re: Nasa is to reveal Mars water secrets...
Post by: Seehund on March 02, 2004, 05:57:11 PM
Quote

KennyR wrote:
Quote
Blobrana wrote:
i`ve got a feeling that mars is crawling with underground lifeforms...er, like the earth...


Well, they obviously don't use sunlight, or Mars would be green. So they would have to live off warmth and sulphides produced by volcanism. Trouble is, unlike Earth, Mars cooled out a long time ago. No more volcanism. So where would they get their energy from?


Organisms don't necessarily have to live off any warmth. Ambient temperatures that don't stop the essential cellular processes from taking place (and possibly creating their own metabolic warmth if need be) should be sufficient.

Photosynthesising lifeforms wouldn't have to be green. If Martian plants/algae/whatever use a chlorophyll-like isozym for photosynthesis it would probably be adapted to Martian light, together with the plants' pigmentation like deep-sea algae, cyanobacteria et c. How long has the Martian sky had the same colour that we see today? An evolutionary significant amount of time? And single bacteria-sized organisms here and there don't really have any discernible colour.

We're still talking about hypothetical lifeforms in a largely unknown environment on another planet, and yet we're applying rather specific Earth biology on our speculations... :) And how should we define "life" on Mars to begin with? Is a self replicating nucleic acid life?
Title: Re: Nasa is to reveal Mars water secrets...
Post by: Seehund on March 02, 2004, 06:05:19 PM
Quote

KennyR wrote:
Quote
Speelgoedmannetje wrote:

And why should it be green on Mars? Maybe there's happening the same, but less/more efficient.


Then where is the oxygen by-product?


It's there, but only 0.6% of what we have on Earth. Then again Mars doesn't exactly appear to crawl with life like Earth. :)

But now we make the IMO rash assumption that the Martian photosynthesis, if it exists at all, works like it does on Earth.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: alx on March 02, 2004, 07:14:28 PM
You can see and hear what's happening here (http://www.nasa.gov/multimedia/nasatv/index.html)
Title: Re: Nasa is to reveal Mars water secrets...
Post by: sumner7 on March 02, 2004, 08:52:05 PM
Quote

alx wrote:
You can see and hear what's happening here (http://www.nasa.gov/multimedia/nasatv/index.html)


Interesting.  :-o
Title: Re: Nasa reveals Mars water secrets...
Post by: blobrana on March 02, 2004, 10:12:18 PM
Hum,
(and for those withut Realplayer...),
so basically NASA  has reported compelling evidence that the tiny crater that the Mars rover Opportunity has been scooting around for the last month was once soaked in water.


"Liquid water once flowed through these rocks. It changed their texture, and it changed their chemistry,.
The finding greatly enhances prospects that Mars was a much more hospitable planet early in its history, possibly even amenable to the rise of life at one time.
There were several key lines of evidence to support the conclusion, including the presence in the rocks of sulphate's and small spherules that were probably precipitated out of water.


The rocks' physical appearance,
http://marsrovers.jpl.nasa.gov/gallery/all/1/m/034/1M131201699EFF0500P2933M2M1-BR.JPG (http://marsrovers.jpl.nasa.gov/gallery/all/1/m/034/1M131201699EFF0500P2933M2M1-BR.JPG)
such as niches where crystals once grew, also helped to prove the case. It seems to have formed in water or, after formation, have been highly altered by long exposures to water. Jarosite may point to the rock's wet history having been in an acidic lake or an acidic hot springs environment.




Pictures from the rover's panoramic camera and microscopic imager reveal the target
http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20040302a/16-jg-02-mi1-B035R1_th200.jpg (http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20040302a/16-jg-02-mi1-B035R1_th200.jpg) rock, dubbed "El Capitan," is thoroughly pocked with indentations about a centimetre (0.4 inch) long and one-fourth or less that wide, with apparently random orientations. This distinctive texture is familiar to geologists as the sites where crystals of salt minerals form within rocks that sit in briny water. When the crystals later disappear, either by erosion or by dissolving in less-salty water, the voids left behind are called ...VUGS!..., and in this case they conform to the geometry of possible former evaporate minerals.
http://marsrovers.jpl.nasa.gov/gallery/all/1/m/033/1M131117272EFF0454P2953M2M1-BR.JPG (http://marsrovers.jpl.nasa.gov/gallery/all/1/m/033/1M131117272EFF0454P2953M2M1-BR.JPG)http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20040302a/07-ss-07-moess1-B038R1_br.jpg (http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20040302a/07-ss-07-moess1-B038R1_br.jpg)


Hum, i thought so...

Title: Re: Nasa reveals Mars water secrets...
Post by: sumner7 on March 03, 2004, 12:47:29 PM
There must definitely be some life form on mars if liquid water has been found.  :angel:
Title: Re: Nasa reveals Mars water secrets...
Post by: cecilia on March 03, 2004, 04:08:24 PM
let's not get nutty!
 :juggler:
it seems there hasn't been water on mars for a looooooog time.

unless something can hybernate for millions of years and if you drop some water on it suddenly wakes up, we ain't seein' no martains.

 :banana:
Title: Re: Nasa is to reveal Mars water secrets...
Post by: Speelgoedmannetje on March 03, 2004, 04:23:39 PM
Quote

Seehund wrote:
But now we make the IMO rash assumption that the Martian photosynthesis, if it exists at all, works like it does on Earth.
Thanks in advance :-), Seehund, to express my thoughts
Title: Re: Nasa reveals Mars water secrets...
Post by: blobrana on March 05, 2004, 07:03:50 PM
Yea, there hasn`t been liquid surface water on-mars for a loooong time...
But just below the surface and maybe to a depth of 20 miles there could be ... and life may continued to survive there...

There have been recent studies of the life forms on earth. And it seems as if there is more bio mass living inside the earth than in the surface seas or jungles...

"The  Spirit rover has also found more evidence that water once existed on Mars, following close behind Opportunity that sits in a region that was soaked by water in the distant past.
 Spirit made its find by studying Humphrey, a 23-inch (60-centimenter) tall rock at Gusev Crater. The rover found that despite the rock's volcanic beginnings, water apparently seeped through it at one time, allowing minerals to crystallize inside.
Extensive studies of Humphrey with the multiple science tools on its robotic arm, which included drilling into Humphrey with the rock abrasion tool (RAT) then taking images of the area with the microscopic imager, Spirit detected fractures in the rock filled with minerals that were most likely formed in the presence of a tiny amount of water."

[Ancestral archaebacteria were probably heterotrophic, anaerobic, sulphur-dependent hyperthermoacidophiles] :-)
Title: Re: Nasa is to reveal Mars water secrets...
Post by: Quixote on March 09, 2004, 11:33:55 PM
KennyR kibitzed:
Quote
Nope, it's a matter of chemistry. At the temperature ranges where water could be used as a solvent for life (0-100C of course), green chlorophyll happens to be the most efficient chemical for photosynthesis. There are other kinds - brown, red...but these are a lot less efficient and are used by plants that don't have any other choice, like deep seaweeds.

;-) Ken, there are trees near my house that are purple.  The color may be due to other elements in the leaves besides the chlorophyll, but the point is that they don't look green to the eye, or camera.
Title: Re: Nasa reveals Mars water secrets...
Post by: Quixote on March 09, 2004, 11:35:32 PM
Cecilia chided:
Quote
unless something can hybernate for millions of years and if you drop some water on it suddenly wakes up, we ain't seein' no martains.

;-) There have been cases of that happening on Earth.  Microorganisms captured in amber for millions of years springing to life once the appropriate environmental conditions were restored.
Title: Re: Nasa reveals Mars water secrets...
Post by: cecilia on March 10, 2004, 12:44:15 AM
I didn't say it was impossible, just that for me to believe anything I need proof.
Being Sceptical is rational.
Title: Re: Nasa reveals Mars water secrets...
Post by: Speelgoedmannetje on March 10, 2004, 05:36:01 PM
Quote

Quixote wrote:
;-) There have been cases of that happening on Earth.  Microorganisms captured in amber for millions of years springing to life once the appropriate environmental conditions were restored.
hum, I thought that evidence was proven false...
that earth microorganisms could have penetrated it.
With the ability of microorganisms to survive everywhere, life could be found on the moon either, since we have been there :lol:

(btw, Quixote, do you got something in your eye? -> ;-))?
Title: Re: Nasa reveals Mars water secrets...
Post by: Quixote on March 10, 2004, 09:25:36 PM
@ Cecilia:

;-) That's fair.  I'm a bit of a skeptic, myself.


@ Speelgoedmannetje:

:lol: Nope.  There is nothing in my eye, but thanks for your concern.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: ivier on April 03, 2004, 10:59:26 PM
Things needed for life on Mars...

Surface :
Warmth - Gets upto 86 degrees F at the eguator around noon (mars time ofcourse). Plenty warm enough, life would just have to hibernate when it gets to cold.

Liquid Water - Areas where the martian atmosphere are higher then normal go above the 'tripoint', where liquid water can exist, though in a smaller tempreture range then earth, in these areas, water can remain liquid between 0 - 10 Centigrade. Areas where the atmostphere would be thicker include deep craters, and massive canyons.

Light - Mars has plenty of light on the surface

Underground:
Liquid Water - Mars is covered in a permafrost that goes very deep into the planet. this permafrost is mostly ice. Mars seems geothermally dormant, but looks can be decieving, unlike earth which 4.8 billion years ago got smacked by a small planetoid, which knocked by a rather sizeable chunk into orbit, and provides enough stress on our crust to keep it thin. Mars has a normal thick crust like most other terrestrial planets. But that does not mean it's asleep, it just means that events happen less often, but on a much larger scale, thus Olympus Mons. So in the deeper parts of the martian crust it is likely warmer, possible with huge ungerground rivers, lakes, and maybe even oceans.

Warmth - see above

Light - we already know that life does not need light

Under the icecaps:
liquid water - liquid water needs 2 things, pressure and heat. the more pressure you have, the less heat it takes.
The martian icecaps are huge, and express a great deal of pressure on the lower parts of the icecap. It is not inconcievable that the pressure under the ice could be great enough, to compress the ice into liquid water, and if theres even one tiny geothermal dome or vent under the ice, it's pretty much assured.

Warmth - having warth is well and good, but life does not actually need it. Seeing as how life lives on or in every continent on earth. Some forms of algae actually live IN artic ice, melting it as they need it, by excreting antifreezes.

Light - life does not need light, only energy, which can come so many ways.


Summary:
Despite Mars' harsh conditions, and the obvious fact that the surface is not infested with martian life, the conditions are there for life to exist across large expanses of the planet. Some are more likely then other to harbor life. Most will be microbial, but maybe some will be large enough to see, and maybe even crawl across the surface. The trick to finding this life, is finding where the conditions exist for the life, and waiting to see them wake up.

AfterThought: It is often stated, that mars is too small to sustain a sizable atmosphere neccessary to sustain a living planet. I believe this to be wholey untrue, but rather, that mars had it's atmosphere destroyed by a very massive impact, after most of the free material in the solar system that could replinish it's atmosphere had dissipated. the evidence is in the southern hemisphere, a crater 6 miles deep. The majority of all life on mars would have parished shortly after this impact, but the oceans would take a long time to evaporate and snow down onto the poles. Life during this time would have been adapting to a collapsing ecosystem, finding nitches where ever they lie. These lifeforms could possibly still be there today. They would likely be so fragile, they the very act of discovering them could kill them. We must tred cautious in our exploration of Mars, and hope we find life, but also that it remains living after we find it.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: KennyR on April 03, 2004, 11:08:40 PM
Quote
Quixote wrote:
Ken, there are trees near my house that are purple. The color may be due to other elements in the leaves besides the chlorophyll, but the point is that they don't look green to the eye, or camera.


Wrong, they do - to a spectrographic camera. Those chlorophyll lines will be there and strong. Mars has no such lines. Therefore, Mars has no photosynthesising life.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: Karlos on April 04, 2004, 02:19:11 AM
Quote

AfterThought: It is often stated, that mars is too small to sustain a sizable atmosphere neccessary to sustain a living planet. I believe this to be wholey untrue, but rather, that mars had it's atmosphere destroyed by a very massive impact, after most of the free material in the solar system that could replinish it's atmosphere had dissipated. the evidence is in the southern hemisphere, a crater 6 miles deep.


I'm not sure about this, but it could be true. However, the reasons given for mars' inability to sustain a dense atmosphere aren't invalid even if the past calamity you suggest is true.

Firstly, if you determine the mean speed of lighter gases such as nitrogen and oxygen for the upper end of the martian temperature scale, you find they are quite close to escape velocity. That's not to say they simply escape into space since the atmosphere isn't warm enough overall. However, if mars was warmed, as is central to so many terraforming ideas, this might be a problem ;-)

Secondly, there is no significant magnetosphere around mars. This allows the solar wind to erode the upper atmosphere unchecked.

Thirdly, even if mars had the same mass of atmosphere as earth, the surface pressure would not be nearly as great simply because the gravitational pull is less.

All that aside, I agree. If there ever was life on mars earlier, I expect it would still be found here and there, simply because once established it's very difficult to eradicate :-)
Title: Re: Nasa is to reveal Mars water secrets...
Post by: KennyR on April 04, 2004, 03:15:17 PM
Quote
AfterThought: It is often stated, that mars is too small to sustain a sizable atmosphere neccessary to sustain a living planet. I believe this to be wholey untrue, but rather, that mars had it's atmosphere destroyed by a very massive impact, after most of the free material in the solar system that could replinish it's atmosphere had dissipated. the evidence is in the southern hemisphere, a crater 6 miles deep.


The atmosphere of Mars isn't thick for one reason - solar wind. Because Mars is so small, its iron core cooled and solidified a long time ago. The magnetism it generated that was protecting the atmosphere disappeared, and the solar wind stripped off what remained of the atmosphere.

It's the eventual end of all rocky planets, although it happens to the smaller ones (or the low-iron ones) first. Earth really is quite exceptional in every way.
Title: Re: Nasa has revealed Mars water secrets...
Post by: blobrana on April 04, 2004, 06:49:46 PM
Yea this is true...
The core has cooled down, (although not quite solid)  and  the protective magnetic shield has gone...

Impacts would have blown away parts of the atmosphere (and planet) into space, but they also (in the early bombardment era) brought water, and frozen gases etc to the planet surface.

The inner planets all started out completely molten, so any water  or gases that we find on the planets today have been transported there by comets and asteroids...
(Quite remarkable, when one looks at earth`s oceans...) :-o
Title: Re: Nasa has revealed Mars water secrets...
Post by: Karlos on April 04, 2004, 07:10:19 PM
Quote

Quite remarkable, when one looks at earth`s oceans...


It seems we weren't the only planet to be awash with water.
Studies of the Deuterium to Hydrogen ratio in the water vapour in Venus' upper atmosphere suggests that an oceanic quantity (ie comparable to the total volume of earths oceans) simply boiled away at some point in it's history.

The ratio of the heavier duterium isotope is much higher there than here.

-edit-

Thinking on the solar wind issue, whilst I don't disagree (as I already posted) the solar wind is eroding it, I am curious as to the extent.

Assuming the solar wind flux/unit area diminishes as 1/(r*r) [it should do considering a constant number of particles emitted with spherical symmetry], given the orbital semimajor axis of mars is about 227 million km compared to earth's 150 million km, so the intensity of the solar wind (per unit area) relative to earth is

F = 1/(r'*r') [where r' = 227/150] = 0.43

....assuming no other losses.

Given mars' smaller radius (about 3390km verus earth's 6370), the total sunward side of mars is exposed to:

T = F * (R' * R') [where R' = 3390/6370] = 0.43 x 0.28

= 0.12

So, a very crude guess that mars is exposed to approximately 12% of the total flux of solar wind we get.

Now, given venus also has no appreciable magnetic field and is exposed to much higher levels of solar wind than mars (given its larger and closer) and retains a vast atmosphere, how much damage to mars' atmosphere is the solar wind producing I wonder?
Title: Re: Nasa has revealed Mars water secrets...
Post by: KennyR on April 04, 2004, 07:48:27 PM
Quote
Karlos wrote:
Now, given venus also has no appreciable magnetic field and is exposed to much higher levels of solar wind than mars (given its larger and closer) and retains a vast atmosphere, how much damage to mars' atmosphere is the solar wind producing I wonder?


Venus has its own Van Allen belts. Even so, it doesn't prevent some of its atmosphere being blown into a torus in wake of its orbit.

The fact that Mars has no thick atmosphere due to solar wind erosion is the current scientific theory right now. I don't know how to check your calculation but 12% does seem rather a little.
Title: Re: Nasa has revealed Mars water secrets...
Post by: Karlos on April 04, 2004, 07:57:21 PM
@Kenny

I'm not disputing the fact that it causes atmospheric erosion, I'm just guestimating the extents.

As for the erosion of venus atmosphere, the point I was making is that if the solar wind has had billions of years to reduce it, why is it still so massively dense? Its true that venus does have its own van allen belts, but the total magentosphere of venus is very weak compared to earth (hinting at some differences in internal state).

As for the calculation, like I said, its a simple inverse square calculation to estimate the solar wind flux at mars' mean distance relative to earths, and that was 0.43.

Then I just factored in the difference in area of the earth and mars. Mars surface area is 0.28 that of earth (if you divide out you get rid of the 4pi terms etc), so it can only be exposed to 0.28 x 0.43 = 0.12 the total flux we are based on it's relative size and distance from the sun.

Perhaps the reasoning is flawed, feel free to play with the figures.
Title: Re: Nasa has revealed Mars water secrets...
Post by: Karlos on April 04, 2004, 08:24:32 PM
Still on the issue of magnetospheres, according to this (http://geology.50megs.com/space/mag/mag.html) geology site, Venus' magnetosphere is 1/25000 the strength of earths.

Hence it can't exactly offer much protection from the solar wind, which is even more intense there (inverse square law again) than here.

Since venus average orbital distance is 108 million km compared to earth's 150 million km, the solar wind flux at it's distance relative to here is 1.92x greater, assuming inverse square relationship again.

According to the same site, Mars' magnetosphere is 1/5000 that of earth, which makes it 5000 times stronger than venus.

So again, how come the atmosphere is still so vast after so long?

Title: Re: Nasa is to reveal Mars water secrets...
Post by: ivier on April 04, 2004, 09:48:17 PM
Myth: Chlorophyll is green
Fact: Most Chlorophyll on Earth is green, BUT alot of it is purple, and has 70% efficiency when compared to green chlorophylls. Green however is NOT neccessarily as efficent as chlorophyll can get, just the most efficient, that earth life has found. 95% of all plant species on earth use green chlorophyll, but theres still the other 4.9999999% using purple. but there are other chlorophylls as well, they are quite rare, usually found in unusual algae and moss.

To say mars has no photosythisizing life because there is no green, is the same as saying, a city has no taxis, because there are no yellow cars.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: KennyR on April 04, 2004, 10:19:20 PM
Quote
ivier wrote:
Green however is NOT neccessarily as efficent as chlorophyll can get, just the most efficient, that earth life has found. 95% of all plant species on earth use green chlorophyll, but theres still the other 4.9999999% using purple. but there are other chlorophylls as well, they are quite rare, usually found in unusual algae and moss.

To say mars has no photosythisizing life because there is no green, is the same as saying, a city has no taxis, because there are no yellow cars.


Chlorophyll B, C and D all have spectral characteristics identifiable by high school students. So if they're there in any quantity they'll have been seen. They weren't. Besides which, A is the most efficient, and it's difficult imagining anything surviving on the less efficient types in an environment as hostile as Mars.

Not only does this city not have any taxis, it has no roads.
Title: Re: Nasa has revealed Mars water secrets...
Post by: KennyR on April 04, 2004, 10:25:27 PM
Quote
Karlos wrote:
So again, how come the atmosphere is still so vast after so long?


Seems I was wrong about Venus having a geomagnetic field. But it seems the very thickness of its atmosphere generates a magnetic field of its own capable of deflecting solar wind. Clicky here (http://www-ssc.igpp.ucla.edu/personnel/russell/papers/venus_mag/) for some in-depth info.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: T_Bone on April 04, 2004, 10:42:41 PM
Quote

ivier wrote:
Myth: Chlorophyll is green
Fact: Most Chlorophyll on Earth is green, BUT alot of it is purple, and has 70% efficiency when compared to green chlorophylls. Green however is NOT neccessarily as efficent as chlorophyll can get, just the most efficient, that earth life has found. 95% of all plant species on earth use green chlorophyll, but theres still the other 4.9999999% using purple. but there are other chlorophylls as well, they are quite rare, usually found in unusual algae and moss.

To say mars has no photosythisizing life because there is no green, is the same as saying, a city has no taxis, because there are no yellow cars.


Hell, who's to say all life would even be carbon based to begin with? here we are looking for green and carbon dioxide, while it's possible there's grey's excreting sand as a byproduct of silicone based respiration.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: KennyR on April 04, 2004, 11:06:24 PM
Quote
T_Bone wrote:
Hell, who's to say all life would even be carbon based to begin with? here we are looking for green and carbon dioxide, while it's possible there's grey's excreting sand as a byproduct of silicone based respiration.


Silicon-based life will never be anything more than sci-fi. Silicon shares many properties with carbon, but it does not form long chains. Carbon forms a bewildering number of compounds. Silicon does not. It's too metallic and doesn't like covalent bonds - especially not with itself.

Silicon makes rocks. Carbon makes chemistry.

It may be boring to most people, but the reason life is carbon based and green is the same way large planets are round - they just can't be any other way.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: blobrana on April 04, 2004, 11:53:42 PM
Hum,
plants are green because the sun is a yellow star, and the earth atmosphere lets in a limited electromagnetic range...

The leaves look green because that part of the spectrum is les energetic and reflected back...(er, leaves are every colour , apart, from greeen...)
I remember that there are a lot of red fish, because the red colour is absorbed by the water, so the fish become less of a target to predators.

As for silicon life forms , i personally can`t rule it out. but, silicon (which can form long chains) are very unstable: and require a cold environment, so chemical reactions would correspondingly take longer...(and silicon based life may require longer than 13 billion years to `happen`)




[it is strange how everything just seems right for life in this universe though (not in a mystical way!)...]
Title: Re: Nasa is to reveal Mars water secrets...
Post by: T_Bone on April 05, 2004, 12:14:14 AM
Quote

KennyR wrote:
Quote
T_Bone wrote:
Hell, who's to say all life would even be carbon based to begin with? here we are looking for green and carbon dioxide, while it's possible there's grey's excreting sand as a byproduct of silicone based respiration.


Silicon-based life will never be anything more than sci-fi. Silicon shares many properties with carbon, but it does not form long chains. Carbon forms a bewildering number of compounds. Silicon does not. It's too metallic and doesn't like covalent bonds - especially not with itself.

Silicon makes rocks. Carbon makes chemistry.

It may be boring to most people, but the reason life is carbon based and green is the same way large planets are round - they just can't be any other way.


For someone so liberal in politics, you sure are an old conservative fart in other areas ;-)

Life need not necessarily be anything resembling that on earth, for all we know, the next lifeform may resemble self reproducing nanobots more than they do organisms.
 

Something just crossed my mind, I wonder if something would necessarily have to be self reproducing to be considered alive?
Title: Re: Nasa is to reveal Mars water secrets...
Post by: whabang on April 05, 2004, 09:52:43 AM
Quote

Something just crossed my mind, I wonder if something would necessarily have to be self reproducing to be considered alive?

There has been certain disputes about viruses' being or non-being, AFAIK.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: T_Bone on April 05, 2004, 11:25:08 AM
Quote

whabang wrote:
Quote

Something just crossed my mind, I wonder if something would necessarily have to be self reproducing to be considered alive?

There has been certain disputes about viruses' being or non-being, AFAIK.


I was thinking more along the lines of, like, say we found GOD  floating around wearing a white robe and smoking a pipe. Ok, maybe not god, but something that's obviously alive/intelligent. Do we actually have to hold him to self replicating in order to consider him alive? Even if the thing is smart enough to argue the point on his own?  :lol:

Never mind... just woke from a really strange Monty Python-esqe dream.  :-P
Title: Re: Nasa is to reveal Mars water secrets...
Post by: whabang on April 05, 2004, 11:34:25 AM
@T-bone
Well, God did have a son, didn't he? :-)
Title: Re: Nasa is to reveal Mars water secrets...
Post by: blobrana on April 05, 2004, 12:49:20 PM
Didn`t she?




[but it could all have been a huge farcical mix-up...
concocted up by a strange desert sect, living on a small planet on the edge of the galaxy...] :-)
Title: Re: Nasa is to reveal Mars water secrets...
Post by: odin on April 05, 2004, 12:52:31 PM
Quote

whabang wrote:
@T-bone
Well, God did have a son, didn't he? :-)

Ah yes, but Jesus *is* God, is he not? :-)
Title: Re: Nasa is to reveal Mars water secrets...
Post by: Karlos on April 06, 2004, 08:49:52 PM
Quote

KennyR wrote:
Silicon-based life will never be anything more than sci-fi. Silicon shares many properties with carbon, but it does not form long chains. Carbon forms a bewildering number of compounds. Silicon does not. It's too metallic and doesn't like covalent bonds - especially not with itself.

Silicon makes rocks. Carbon makes chemistry.



I agree that silicon based life isn't likely, but the rest of the statement is not entirely accurate. Whilst silicon doesn't enjoy forming bonds with itself, the sp3 hybrid derived sigma bond is known for Si-Si just like carbon and a whole bunch of silanes comparable to the alkanes are known. There are even compounds that have a 3p - 3p pi bond (but you have to put rather large blocking groups on the silicon.

However, they seriously don't like exposure to free oxygen :-)

As for general silicon chemistry, virtually all compounds of silicon are toward's the covalent end of the bonding spectrum. The only thing approaching ionic silicon compounds are alkali / alkaline earth metal silides, careful hydrolysis of which was the first practical preperation of the silanes above.

As for the number of compounds, the Si-O-Si linkage is almost as versatile as the C-C linkage and there are an inestimatable number of possible combinations based on silicon-oxygen chains.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: ivier on April 06, 2004, 11:47:02 PM
Quote
However, they seriously don't like exposure to free oxygen  :-)


TRUE, but, long chain carbon molecules don't like oxygen either, infact most early life was killed by oxygen.

The whole reason oxygen breathing organisisms dominate the planet earth (right behind carbondioxide breathers) is this.
Most methane breathers exhale oxygen, most carbon dioxide breathers exhale oxygen, most(all?) oxygen breathers exhale carbon dioxide.

So while early earth was saturated in methane and carbon dioxide, most things produced alot of oxygen. When methane breathers breathed oxygen, they litterally burned up, too much energy at once. carbon dioxide breathers choked on the oxygen.

 The oxygen continued to rise uncontrolled, eventually escaping into the atmosphere. mixing in the atmosphere with vast amount of methane ofcourse resulted in a very explosive atmosphere. Lightening would spark vast firestorms that would race across the sky, devouring the methane, and the oxygen, producing alot of carbon dioxide. The methane breathers gasped for breathe as the methane was rapidly depleted. Most ofthe methane breathers died, leaving only the ones clutching to life in the bottoms of the deep oceans. Meanwhile a new form of life had come around, an oxygen breather, it stayed close to the carbon dioxide breathers who were busy producing oxygen from the almost completely carbon dioxide atmosphere.

now we all know that carbon dioxide is a green house gas, but what you might not know, is methane is a much better greenhouse gas, the world has been kept at a good warm tempreture in the early solar system, when the sun was a little bit cooler, the loss of the methane resulted in the first of many ice ages to come, the big ice age, snowball earth. Glaciers covered the continent(s) [this is pre-pangea], the oceans froze over, the ice at the equator was hungreds maybe even thousands of feet deep. The world was seemingly dead. Beneath the ice, life continued, co2 breathers clung to the ice, straining to feel the light that only barely trickleded through (ice being less dense then water allows light deeper down, though more scattered) the o2 breathers hung close to thier vital air supply. some of the o2 beathers eventually started munching on the co2 breathers, which threatened the vital o2. other o2 breathers responded by munching on the 'herbivores'

Above the ice, as the sun grows still hotter, the co2 starts playing it's role as a greenhouse gas and the world over tho course of 100,000 years begins to defrost. When the first openings in the ice occurs, the 02 escapes into the atmosphere, slowing the warming process. it will take a million years before the ice fully recedes into nothing more than caps.

The co2 breathers at the gaps explode in numbers, and produce massive amounts of o2, the o2 breathers explode in numbers as well, consuming the o2 almost as fast as it's produced, but massive amounts of the cooling o2 gas still makes it's way into the atmosphere, to play havoc at a later date. in the ice gaps near land, some of the plants, make thier way onto living on shore, just a slime at the edge of the oceans. some of the minute animals, also pull thier hard exoskeletal bodies to shore, and feed on this slimey plant life.

The bugs find the reproductive parts of the plant to be the most nurishing, so the plants that keep those parts highest out of reach of the bugs survive more often, they quickly grow to an inch in height, far from the mearly microscopic bugs reach. some of the bugs respond, by learning to jump, others devolop pointy protrusions which gives them a better grip for climbing or pulling, while others devlop both. The plants grow still taller, and taller stretching upwards, to a foot, then a meter, and tens of meters. some of the bugs eventually grow wings, and learn to fly, and thus began the age of insects, and the end of snowball earth.

Snowball earth was the 2nd cataclysm (that i know of). the first created the moon, which would shape life for thousands of millenia to come.

-- Back to Mars --

Mars is in a very extended snowball stage, one that is difficult to recover from, but all it would have taken is a single microbe to survive the initial cataclysm, and mars will be teeming with life, across its surface, probably single cellular, or maybe even sub scopic multicellular. the conditions of mars are not friendly enough for anything much larger then a large flea. such creatures will likely stay very close to thier food source, maybe even farming it like some ants do. most likely in underground colonies, where they can control the enviromental conditions somewhat.

Martian colonial creatures might do various things to improve thier living conditions. One that seems quite possible, but that i have not even heard of earth life doing. Is pressuring thier underground colonies, with a series of airlocks. The airlocks (and all walls of the colony) would be made of some excreted material which is consumed and re-excreted to open and close them. inside the colony, the creatures would have a larger tempreture range in which water could exist in liquid form.

The tempreture would be kept in this range by collections of well fed organisms,  which constantly vibrate thier bodies to generate heat.

Pressure would be maintained by some of the creatures going outside, taking a deep breathe, and going back inside to exhale it.

To gather liquid water for thier gardens, they would likely excrete an antifreeze onto some frost in the early morning to melt it, then sip it up.

If thier gardens required atleast some light, i could see them packing the 'martian plants' into thier bodies and taking them to the surface at dawn, keeping thier insides pressurized for the benifit of the gardens, and laying in the sun until dusk. during this time they would be tended by others of thier colony providing water and nutrients the gardens would need during the day.

There would ofcourse also be solitary creatures which raid the colonial creatures nests, for food, wither it be the colonial creatures themselves, or the gardens they tend.

The raider would either have a burrow of it's own, that it hordes it's food in, or it would freeze solid at night and hibernate, or maybe even live in the colonial creatures nest, pretending to be one of them.

The colonial creatures would have to defend thier nest from these raiders, so they would likely develop methods of fighting simular to the colonial insects of earth. apon being detected the raider would be clobered by hordes of the colonial creatures, dismembered, and used as a mulch in thier garden.

The point of this post is ofcourse, that if something survives a global catacysm it will likely adapt, the life of earth adapted to being frozen over (on multple occasions). If any life on mars survived, it will have adapted and still be there, but we probably won't see it, unless it crawls across the camera lens, because it'll be quite small. Only in abundance do things grow very big, and we can plainly see mars does not have anything other then reddish soil and ice in abundance.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: blobrana on April 07, 2004, 12:38:19 AM
Hum,

There is more biomass inside the earth than on the surface (http://mysite.freeserve.com/blobrana/features/news/bioearth.html)

On mars there is an abundance of sulphur, hydrogen, c02 etc...
more so deep down, say 5 to 20 mile deep...in solid rock, no need for cracks or `air pockets`...

i imagine that there are a few earth life forms that would easily survive those harsh Martian conditions...




[remember Dune?]
Title: Re: Nasa is to reveal Mars water secrets...
Post by: ivier on April 07, 2004, 02:24:36 AM
Quote
There is more biomass inside the earth than on the surface


quite true, but finding subterrainian life on mars is difficult, especially deep subterrainian, it's much lass likely to find them with any near future prove, than anything living just below or even on the surface.

i personally hope for the pressurized nest, insect like creatures.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: Karlos on April 07, 2004, 02:52:30 AM
Quote

ivier wrote:
Quote
There is more biomass inside the earth than on the surface


i personally hope for the pressurized nest, insect like creatures.


I think you might be waiting a long time for that one. I can't imagine the pressurised environment being feasible. Aside from the sheer maintainance problem, the idea of insect like creatures going outside and inhaling atmosphere in an average 6mb environment is a bit hard to take seriously.

If life is present on mars, its likely to be hardy, microscopic and probably underground.

As blobrana points out, there are plenty of terrestrial organisms that could survive martian conditions without the elaboration. And nothing succeds like simplicity, or so they say :-)
Title: Re: Nasa is to reveal Mars water secrets...
Post by: ivier on April 07, 2004, 04:03:21 AM
Quote
I think you might be waiting a long time for that one. I can't imagine the pressurised environment being feasible. Aside from the sheer maintainance problem, the idea of insect like creatures going outside and inhaling atmosphere in an average 6mb environment is a bit hard to take seriously.


i think you do not fully appreciate how thick the martian atmosphere really is, NASA is designing planes to fly high above it's surface. global sand storms which as you know are caused by winds, rework the planets looser surface on a yearly basis, and erode away at all geologic structures. The atmosphere is just too thin in MOST places for liquid water.

the creatures would not have to have much of a pressure increase to keep thier homes always above the water tripoint, there are places on mars where this already occurs, the deepest/warmest regions, like canyons, near the equator! Life on mars would have to adapt to the conditions there in order to survive, the pressurized colony is the only thing no earth life form does, and thats because no earth life form needs to.

obviously underground mars is likely to be pulsating with microscopic life. i was trying for something a little more complex and just as likely in my description. mars has been around about as long as earth, thats a LONG time for life to advance, and it WILL have advanced, and just possibly into the very small scopic range. it can be easily seen that an insect like design would be well suited to harsh conditions, but if they are farming any sort of garden, they will tune thier enviroment to best suit thier crop. just as colonial insects of earth do. earth insects carefully maintain the temperture and humidity of thier nests, and many of them DO excrete a rather hard material to reinforce thier nest walls, it is not a far stretch to seal off the tunnels to create an airlock. the martian bugs, and thier garden food, would probably (but not neccessarily) need to have already evolved (but not neccessarily thier relation) before the oceans and atmosphere were stripped, the bugs would be more adaptive then thier food supply.

if it was a slow leaking of the atmosphere into space as some believe then they would most definately had plenty of time to adapt. if it was a sudden event, as i suggested, with a massive impact destroying the atmosphere, then there will be a much smaller chance of such an adaptation is far less likely, but still possible. the earliest forms of life adapt the quickest.

As for maintainance, kick an antpile sometime. yes a rather bad maintainance problem, but colonial insects are anything but lazy. they will work themselves to death for the good of the hive. the nest design would likely have many chambers, with airlocks between each chamber, incase of breech. but being mars, there is little to disturb thier nest, what would cause a breech? heh, i'm not a short sighted hypothisizer, the raider bugs, for one. or the yearly sand storms. the latter of which would likely result in the nests being rather deep in the ground
Title: Re: Nasa is to reveal Mars water secrets...
Post by: T_Bone on April 07, 2004, 01:46:09 PM
Well, if we do find insect like life on Mars, I for one say we strike first!  :destroy:

We've got enough damn bugs already!
Title: Re: Nasa is to reveal Mars water secrets...
Post by: blobrana on April 07, 2004, 02:20:43 PM
Hum,
i feel a starship trooper thread coming on....



(http://www.reelmoviefx.com/troopercloseup_465x272.jpg)
Title: Re: Nasa is to reveal Mars water secrets...
Post by: KennyR on April 07, 2004, 02:57:36 PM
Insects are not the ideal life form for low oxygen environments anyway. They don't even have lungs. Or haemoglobin, for that matter.
Title: Re: Nasa is to reveal Mars water secrets...
Post by: Karlos on April 07, 2004, 05:22:12 PM
Quote

ivier wrote:

i think you do not fully appreciate how thick the martian atmosphere really is, NASA is designing planes to fly high above it's surface.

...

the creatures would not have to have much of a pressure increase to keep thier homes always above the water tripoint, there are places on mars where this already occurs, the deepest/warmest regions, like canyons, near the equator! Life on mars would have to adapt to the conditions there in order to survive, the pressurized colony is the only thing no earth life form does, and thats because no earth life form needs to.


I do appreciate the density of the martian atmosphere. It's low. Flying an aircraft is one thing - a lightweight design is feasable, especially given the lower gravity needed for the lift to overcome. Absolute density of the air is the key factor for aeronautical considerations, the absolute pressure is of lower concern. Although the two are directly related, they are not the same.

To clarify that remark, even if mars had an atmosphere at the same density as earth, the pressure would still be much less as the force exerted depends on the gravitational pull.

Going back to living systems, there are a great many things beyond the triple point of water that would affect chemical/biological properties. For one thing, the solubility of gasses decreases sharply with pressure.

When you consider how insoluable molecular oxygen is at STP here on earth, you can see that even at an optimistic 10mb pressure at the bottom of say Valles Marineris, a small puddle of water (likely to already be highly saturated with minerals) would mean that no appreciable trace of oxygen could stay solvated. Only extremophile, probably anerobic, microscopic life forms are likely to find this surface conditions endurable.

For anything more advanced, like insect life, solvating gasses in its bodily fluids (or whatever rudimentary circulatory system it may have) is likely to be inordinately difficult even at several times the mean surface pressure of the outside. Just look at the binding efficiency curve of myoglobin / haemoglobin and other oxygen binding systems here (all very efficient at their job) versus the partial pressure of O2. It falls off very sharply as the pressure falls.

This is one reason why higher animal life on earth struggles to survive at altitudes where the overall pressure, proportion of oxygen, and temperature ranges are still much more tolerable than mars.

Given the idea life conquers all extremes, the lack of any higher organisms at these altitude on earth suggests that mars, where the pressure is already far lower, atmospheric oxygen is about 0.13%, harsh infiltered solar radiation and extreme temperature shifts, the likelyhood existance of anything beyond extremophile life becomes even more remote.

Quote

if it was a slow leaking of the atmosphere into space as some believe then they would most definately had plenty of time to adapt. if it was a sudden event, as i suggested, with a massive impact destroying the atmosphere, then there will be a much smaller chance of such an adaptation is far less likely, but still possible. the earliest forms of life adapt the quickest.


It's not impossible both are responsible. An earlier cataclysmic loss of atmosphere is possible, given some of the massive impact sites, but whatever atmosphere remained is being scavenged by the solar wind, if the measurments made by some of the first probes to orbit the planet are to be accepted.