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#26 2003-01-25 20:05:40

soph
Member
Registered: 2002-11-24
Posts: 1,492

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]earth's oceans are what, 7 km?  those depths are just fine!  I wonder if we can ever import earth marine life into martian oceans...that would be awesome.[/color:post_uid0]

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#27 2003-01-25 22:59:23

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 6,215
Website

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]The media loves a scoop. The first time new information comes out it is multiply announces. When you provide an update regarding the same information the media has the reaction of "been there, done that". This is not scientifically valid, but it is the way the media reacts.[/color:post_uid0]

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#28 2003-01-25 23:12:41

Josh Cryer
Administrator
Registered: 2001-09-29
Posts: 3,830

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]Indeed Robert.

“Our predictions were true,” is infinitely boring to the media, and perhaps to the commoner, also (the common American requiring sensationalism for anything to be remotely interesting). If we were a scientifically inclined society such a discovery would be a call for celebration! Our predictions are true and our models are more accurate!

But I digress. I don't think it's such a big issue. Anyone have any good knowledge of calculus? We should be able to create a relatively accurate watershed model now...[/color:post_uid0]


Some useful links while MER are active. Offical site NASA TV JPL MER2004 Text feed
--------
The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.

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#29 2003-01-26 01:42:11

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid3]Hi Robert and Josh!

    I suppose you're right. I tend to get excited over this stuff and lose track of the fact that the majority of people couldn't give a damn about it! For most, a rise in the price of a beer is infinitely more newsworthy than a 2.5 km-deep ocean on Mars.

Hi Soph!

    A quick google-check reveals that the average depth of Earth's oceans is approximately 3.2 kms (2 miles). The Indian and Pacific Oceans are about 4 kms deep, on average, while the Arctic Ocean averages only about 1 km.
    So yes, you're quite right in commenting that a 2.5 km Martian Ocean would be "just fine!" I agree it would compare very favourably with Earthly oceans!
    Incidentally, Cindy began a topic in 'Acheron Labs'-Water on Mars' called 'H2O, where'd it go?'. A brief exchange of opinions on introducing Terran species into Oceanus Borealis ensued ... in case you're interested.

                                            smile[/color:post_uid3]


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#30 2003-01-26 04:33:27

Josh Cryer
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Registered: 2001-09-29
Posts: 3,830

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]Could you enlighten us how you came to that number, though, Shaun? Did you do some fancy calculus and so on to get to it, or is it a rough estimate?[/color:post_uid0]


Some useful links while MER are active. Offical site NASA TV JPL MER2004 Text feed
--------
The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.

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#31 2003-01-26 08:51:40

soph
Member
Registered: 2002-11-24
Posts: 1,492

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]i meant at its deepest-at the trenches.  i had thought it reaches 4-5 miles at some point.[/color:post_uid0]

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#32 2003-01-26 19:44:13

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid3]Sorry Soph!
    Looks like I misinterpreted your comments. You're right, of course, that the deepest trenches here on Earth are way deeper than 3 or 4 kms. From memory, the Challenger Deep drops down over 10 kms!! (Doesn't qualify for a recreational dive site! )

Hi Josh!
    I assume the figure you asked about is the 2.5 km depth of Oceanus Borealis I came up with?
    I certainly didn't use a lot of fancy calculus ... I'm not that intelligent!! I left all that to Dr william Boynton of the University of Arizona, principal investigator for Odyssey's gamma-ray spectrometer. He was interviewed by Dr David Whitehouse, the BBC News Online science editor and was reported to have estimated that 'if Mars were to become much warmer for some reason and the ice melted, it would drench the planet to an average depth of between half and one kilometre'. (Dr Whitehouse's words, not Dr Boynton's, according to GOM's post in this thread on May 28 '02).

    When they say stuff like 'cover the planet to a depth of half a kilometre', they're estimating that depth based on an idealised spherical planet with a radius equal to the average radius of the actually quite-irregular-shaped-planet itself. If they tried to take into account every crater, dry valley, tectonic rift, impact basin, and uplifted massif, the calculus would doubtless stump a warehouse full of supercomputers!! (Though I'm led to believe quantum computers will be able to solve such problems with ease ... if they prove practicable.)

    So I started with somewhere between 500m and 1000m of water, from the southern hemisphere discoveries alone. Always trying to err on the side of caution, so as not to be found guilty of overstating my case, I chose the lower figure of 500m.
    In October 2002, Dr Boynton said: "We are really excited about what we are seeing in the north polar region of Mars. With the seasonal carbon dioxide frost gone, we can see evidence of massive amounts of water ice in the soil, even more than we found in the south."
    Being cautious again, I took this to mean I would be very safe in assuming at least another 500m of water, planetwide, would become available if Mars were warmed up.

    So, in total, we are told we could submerge a perfectly spherical Mars in 1000m of water, at the very least, based on Odyssey's data.

    Of course, Mars is anything but perfectly spherical. As we all know, the northern half is some kilometres lower than the southern half. But it's not quite a 50:50 split, with Arabia Terra and the Tharsis Bulge encroaching on the northern lowlands.
    A reasonable guesstimate of the situation is that 60% of Mars is highlands and 40% is lowlands. (This is my own guesstimate and you may want to challenge it. But, even if it is wrong by a few percent either way, it won't make a radical difference to the outcome - remember how much conservatism we built into the figures for the amount of water.)

    Using very simple arithmetic (which my limited abilities oblige me to use!! ), all we have to do is concentrate a planetwide 1000m layer of water onto only 40% of the surface.
    Hence we obtain an ocean with an average depth (again ignoring localised topographical variations) of 1000/0.4, which equals 2500m or 2.5 kms. The topography of Vastitas Borealis will mean some areas will be shallow and some very deep, just like Earth's oceans, but the overall result still holds.

    And if I'd taken the other end of the range for the theoretical water depth available, we would have had 1000m from the south and over 1000m from the north - say, 1200m - making a planetwide depth of 2200m.
    This would lead, by the same process, to an Oceanus Borealis with an average depth of 5.5 kms (over 18,000 feet) !!

    Interestingly, I've just noticed that this range of possible depths of a northern Martian ocean, 2.5 to 5.5kms, fits in very well with an estimate I arrived at back on Nov.12th '02 in 'Water on Mars' - "Mars is hiding something amazing". One man's view', using the controversial snowball comet theory.
    That guesstimate, based on an entirely separate line of reasoning, gave a possible average depth for Oceanus Borealis of about 4 kms ... smack dab in the middle of the range we arrived at here!
    I admit there is way too much guesstimation going on in both cases to read too much into the similarity of the results. But it is thought-provoking that they're so firmly in the same ball-park.

    Any comments?
                                             smile[/color:post_uid3]


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#33 2003-01-30 18:07:23

Nirgal82
Member
From: El Paso TX, USA
Registered: 2002-07-09
Posts: 112

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]Anyone have any figures regarding how much they found and where specifically.
The maps i find only show concentrations, it doesn't give units however.  Like how much water per cubic meter of regolith is there in the areas of greatest concentrations.

Anyone else notice what crap luck we've had with the landers that returned data.  Viking 1 and Pathfinder landed in places where there is virtually no water, and Viking 2 landed on the dry side of a region that borders wet from dry (maybe why we saw frost at Utopia and not at Chryse)

Also, there seems to be more wet areas than dry areas, I took the liberty of translating the data (more or less) to my Mars globe by outlining areas of particular wetness and particular dryness, leaving the middle ground un outlined.
Doing this it has become apparent that Mars isn't actually a desert world, it is only so cold that the atmosphere cannot hold humidity.

If anyone knows how, and can do the math, we should find out if Mars has more or less water than earth proportionally.

These are all tremendous findings and it makes me sick to see how they are ignored, remember when clinton was pres and they practically stopped the presses to announce that they found some TRACES of water SEEPAGE on VERY FEW locations on Mars.  And now they've found oceans worth of water a meter or less below most of the surface, but it gets no major press WHATSOEVER.  Well, it looks like we have to go without a major press conference this time (but even if I was ignorant to Mars, as an american I'd like to see the results of what we as taxpayers payed for)

People have claimed that they have seen pools of standing liquid (possibly hyper saline) water in craters south of -60*S.
This was backed up by finding all that water last year in the south at just those latitudes.
I myself have seen many features whos simplest explaination is pools of standing water with something floating in it, and the "defrosting sand dunes" designation for some of these images in the MSSS MOC gallery isn't cutting it for me.
Maybe we can find some of these features in the north and make a hard correlation between water concentrations and the locations of these "pools"

I will post again with an image number or link for one of these southern "pools" I am talking about.
I myself am not convinced that these are pools, however that would be the simplest explaination for those features...

-Matt[/color:post_uid0]


"...all matter is merely energy condensed into a slow vibration.  We are all one consiousness experiencing itself subjectively.  There is no such thing as death, life is only a dream and we are the imagination of ourselves."  -Bill Hicks

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#34 2003-01-30 22:32:43

Josh Cryer
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Registered: 2001-09-29
Posts: 3,830

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]Well, the GRS data indicates that the regolith is about 50% water ice 50% dirt (other minerals) up until about a third of the way to the equator. This is about a meter or so and gradually becomes less as you approach the equator. So with some integration, it shouldn't be hard at all to figure out how much water is there at the very [i:post_uid0]minimum[/i:post_uid0]. Edit, hmm, didn't realize the post Shaun was referring to was in this very thread.

Here's an image that sort of helps depict what I'm saying:
[img:post_uid0]http://photojournal.jpl.nasa.gov/browse/PIA03803.jpg[/img:post_uid0][/color:post_uid0]


Some useful links while MER are active. Offical site NASA TV JPL MER2004 Text feed
--------
The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.

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#35 2003-02-22 19:02:07

Phobos
Member
Registered: 2002-01-02
Posts: 1,103

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]Did anyone see that article over at Space.com not too long ago about the Martian icecaps being mostly water?  It appears that some of the surface markings on Mars near the caps might actually have been caused by snow.  I'm [i:post_uid0]really[/i:post_uid0] hoping all of these finding on Martian water hold up and don't turn out to be some kind of fluke.  It's hard to get your hopes up in this world.[/color:post_uid0]


To achieve the impossible you must attempt the absurd

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#36 2003-02-22 19:10:44

soph
Member
Registered: 2002-11-24
Posts: 1,492

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]Yeah, i think everyone at the SdC forums saw that smile[/color:post_uid0]

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#37 2003-02-22 19:22:44

Josh Cryer
Administrator
Registered: 2001-09-29
Posts: 3,830

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]Ever since the MOLA data, I've always maintained that the residual caps were water ice, or at least the north residual cap!! I really am surprised people are making it seem like a revalation of sorts. We knew from when Viking was there that there was water vapour in the atmosphere above the north residual cap during the summer. And temperature models from MGS show us that most of the CO2 would have certainly evaporated by midsummer.

But how does water snow differ from CO2 snow? Can CO2 snow?[/color:post_uid0]


Some useful links while MER are active. Offical site NASA TV JPL MER2004 Text feed
--------
The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.

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#38 2003-02-22 19:26:29

soph
Member
Registered: 2002-11-24
Posts: 1,492

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]I believe it's because H2O is an essential compound in forming life (have you ever seen those "organic soup" contraptions, where they filter in atoms, which coalesce into organic compounds spontaneously?).  Water is the key ingredient. 

Another side note-CO2 is a greenhouse gas, useful for terraforming.

So this "discovery" is much much better for life, and a slight setback, stressing slight, for terraforming.[/color:post_uid0]

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#39 2003-02-23 11:43:39

dicktice
Member
From: Nova Scotia, Canada
Registered: 2002-11-01
Posts: 1,764

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]The latest explaination by Cal's Dr. Philip Christiansen, in "Nature," and his interview on Canadian Broadcasting Corporation's "Quirks and Quarks" popular science program (Radio One), last Saturday, claims the gullies on slopes inside Mars craters were formed by running melt-water, beneath retreating snowfields dirty enough to absorb sunlight and shallow enought to melt in contact with the soil thus warmed--evaporation and/or oblation being prevented by the snow cover. The dried-out gullies then remain "plastered" on the slopes when the snow has gone. The process must be going on as I write, since snow fields are in retreat at this stage of Mars's climate. So...what're we waiting for? Let's hypothesize away--how to go about exploring Mars in the vicinity of the retreating snow fields--by tunneling? I expect so, since this would provide UV, etc. shielding at the same time.[/color:post_uid0]

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#40 2003-02-27 01:00:11

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid9]How thick is this snow?
    I've always thought of snow on Mars as being more like a light dusting - perhaps more like centimetres deep rather than metres or tens of metres.
    Still, I suppose if it's had thousands of years to build up ...
    Anyone got any figures?
                                         smile[/color:post_uid9]


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#41 2003-02-27 18:12:00

dicktice
Member
From: Nova Scotia, Canada
Registered: 2002-11-01
Posts: 1,764

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]Christiansen's paper in "Nature" isn't on our library shelf at the moment, for verification, but I recollect him stating in his interview that "one to two metres" of packed snow would allow visible sunlight to penetrate to soil-level, trap the resulting infrared beneath the "greenhouse" created by the snow, and prevent the melt-water from evaporation and/or sublimation. The edges of the retreating snowfields on these slope would thin-down glacier-wise, to provide the necessary thickness range...meaning that water saturated surface soil would be produced continually for as long as the snowfields retreat--like now for instance. Neat, eh?[/color:post_uid0]

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#42 2003-02-27 18:31:18

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid5]Pretty neat, all right!
    Just imagine standing on Mars in the middle of a light wispy snowfall!!
    An event so Earthly-familiar but on an alien planet!
    Call me an incurable romantic or whatever, but it honestly gives me goosebumps just thinking about it.
                                      smile[/color:post_uid5]


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#43 2003-02-27 18:45:16

dicktice
Member
From: Nova Scotia, Canada
Registered: 2002-11-01
Posts: 1,764

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]I would definitly call you a romantic. You'd have to be under a retreating roof of melting snow...like some kind of bug. And the snowflakes will have fallen ages ago! The main thing is, water may be had for the asking, once there--for whatever purpose[/color:post_uid0]

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#44 2003-02-27 22:25:11

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid11]Yeah, you're right!
    I know exactly what you're talking about with the ice-protected streams of water. And I do understand that the snow you mention probably fell millenia ago when one or other of the Martian poles was tilted more towards the Sun. And I understand that it's the availability of water for future manned missions you are stressing.
                                   smile

    I should apologise to you for drifting way off the point and letting my imagination get the better of me!
    For me, Mars has always been a romantic place - I don't just learn about it from all the new data which comes back to us from the probes, I [b:post_uid11]feel[/b:post_uid11] it!! Like thousands of others, I suppose, there's just something about Mars which gets into your marrow ... something difficult to explain.
    So yeah, you're absolutely right. When it comes to Mars, I'm a wide-eyed, passionate, hopeless romantic!

    Sorry, Dicktice! I'll try harder to control myself!!
                                    big_smile[/color:post_uid11]


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#45 2003-02-28 16:49:07

dicktice
Member
From: Nova Scotia, Canada
Registered: 2002-11-01
Posts: 1,764

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]You're not "sucking up" I hope.... My first exposure to Mars lore was pictures of Lowell's drawings, then thought to be accurate representations made when the "seeing" in the mountains outside Flagstaff was good. Now HE was a romantic! No, these latest findings, and the really good resolution views from orbit, showing the actual terrain, have been so long in coming for one of my advanced years, that I hate to see their interpretation squandered--since MY dream of living to see the first humans on Mars probably won't happen (sob), but hypothesizing about it via mutual discussion within this group of "crazies" is possible. I would like to see more science fiction dealing with the subject, set in the not too far distant future, and relegated to do-able in (if not mine, your) lifetime engineering feats...as opposed so-called "antigravity," "space elevators," "terraforming," and the like. Because--like Arthur C. Clark's novel "Prelude to Space"-- such realistic stories can stimulate achievements by up and coming engineers and technicians. You'll note, I avoid mentioning Scientist...their achievements are ongoing, and need no such stimulation.[/color:post_uid0]

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#46 2003-02-28 20:53:22

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid2]Not 'sucking up', honest! Just apologising for daydreaming.
                                 smile

    I would be the last person to want to ruin anybody's dreams - especially if they've been a long time coming. I ain't no spring chicken either!![/color:post_uid2]


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#47 2003-06-10 07:09:09

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid11]I read something today which made me uneasy.
    As many of you probably know, I've made no secret of my belief (shared with many, of course) that Mars has been very wet in the past. I've even gone so far as to say I think there may have been several episodes of comparatively mild climatic conditions there - possibly up to relatively recent times. To me the evidence seems overwhelming.

    That's why this article jarred so badly when I read it!
    To save time for those who have better things to do, here is the nitty gritty:-

Analyzing the spectra from the ten different bands of infra-red light the instrument can detect, the THEMIS team has begun to identify specific mineral deposits, including a significant layer of the mineral olivine near the bottom of a four-and-a-half kilometre deep canyon known as Ganges Chasma. Olivine, Christensen notes, is significant because it decomposes rapidly in the presence of water.
    "This gives us an interesting perspective of water on Mars", he said. "There can't have been much water -ever- in this place. If there was groundwater present when it was deep within the surface, the olivine would have disappeared. And since the canyon has opened up, if there had ever been water at the surface it would be gone too. This is a very dry place, because it's been exposed for hundreds of millions of years. We know that some places on Mars have water, but here we see that some really don't."[/quote:post_uid11]

    Looking at a topographic globe of Mars, it seems virtually impossible that the northern hemisphere could have been inundated with water while the floor of Ganges Chasma remained bone dry.
    Just east of Ganges, lie some of the largest and most obvious outflow channels anywhere on the planet, including Tiu Vallis and Ares Vallis. In fact, quite recently, I remember reading about researchers who found strong evidence that large volumes of water have flowed northward from Argyre Planitia periodically throughout much of Martian history - discharging onto the northern plains via Tiu and Ares.
    Much of this vast and obvious channel network is clearly as much as 2 kilometres [b:post_uid11]higher[/b:post_uid11] than the floor of Ganges Chasma!
    It beggars belief to imagine that such huge amounts of water could have somehow bypassed Ganges, leaving its olivine pristine and dry.

    There's something wrong with this picture!!    yikes

    I can't reconcile this new information with my current worldview of Mars. Since the weight of evidence for large quantities of water seems, at least to me, irrefutable, I have to doubt Christensen's olivine.
    Does anyone know whether the THEMIS instrument is capable of a false identification of such a mineral?
    Or is there some way Ganges could have been isolated from so much water somehow?    ???[/color:post_uid11]


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#48 2003-06-11 07:12:51

dickbill
Member
Registered: 2002-09-28
Posts: 749

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]

Analyzing the spectra from the ten different bands of infra-red light the instrument can detect, the THEMIS team has begun to identify specific mineral deposits, including a significant layer of the mineral olivine near the bottom of a four-and-a-half kilometre deep canyon known as Ganges Chasma. Olivine, Christensen notes, is significant because it decomposes rapidly in the presence of water.[/quote:post_uid0]
Hi Shaun,
I checked in my mineralogy book, Olivine are beautiful  green clear crystals of magnesium and iron silicates. Olive green to  yellowish, brown to alteration (by water I assume ?), heavy (3.2 to 4.2 depending of iron content, spec. grav. ) and fragile. It mentions that as the iron content increases, specific gravity increases, SOLUBILITY increases and fusing point lowers. Olivines  are very abondant in basalts or volcanic rocks, but they can also form in metamorphosed dolomitic limestone
(metamorphic originaly sedimentary ).
I guess that in the case of MArs, the olivine are found in basalts, lava etc, formed during volcanic processes.
Is it possible that the catastrophic floods were too short to dissolve all the olivines ? or alternatively that the floods actually carved Ganges Chasma, dissolving all olivines present, but also revealing new layers of rocks containing olivine as the flood carved more and more the canyon ?
The olivine observed could just be a remnant of a huge initial stock pile.
The problem of long term water on early Mars is not the water, is why the water could stay liquid so long with a fainter sun, or asked otherwise, how likely was the early Mars atmosphere denser with greenhousing characteristic, strong enough to sustain liquid water ?
Maybe the "intermitent warming" theory is right: meteor impacts and volcanism were the only cause of liquid water presence on early Mars, causing huge but very short (hundreds of years, sometimes shorter) catastrophic floods. Hopfully we'll know one day.[/color:post_uid0]

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#49 2003-06-11 08:09:18

dickbill
Member
Registered: 2002-09-28
Posts: 749

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid0]well, certainly volcanism standed longer than hundreds of year, in this case liquid water could be something possible close to the big volcanoes.

about olivines, I also find this ref :


[b:post_uid0]J Mol Evol. 1979 Dec;14(1-3):103-32.     Related Articles, Links

Frost-weathering on Mars: experimental evidence for peroxide formation.
Huguenin RL, Miller KJ, Harwood WS.
A laboratory study of the interaction of H2O frost with samples of the minerals olivine (Mg,Fe)2SiO4 and pyroxene (Mg,Fe)SiO3 at -11 degrees C to -22 degrees C revealed that an acidic oxidant was produced. Exposure of the frost-treated minerals to liquie H2O produced a sudden drop in pH and resulted in the production of copious O2(g) (as much as approximately 10(20) molecules g-1). Exposure of frost-treated samples to 5 ml of 0.1M HCOONa solution resulted in the rapid oxidation of up to 43% of the formate to CO2(g). These reactions were qualitatively similar to the chemical activity observed during the active cycles of the Viking lander Gas Exchange and Labeled Release Biology experiments. Attempts to identify the oxidant by chemical indicators were inconclusive, but they tentatively suggested that chemisorbed hydrogen peroxide may have formed. The formation of chemisorbed peroxide could be explained as a byproduct of the chemical reduction of the mineral. The following model was proposed. H+ was incorporated into the mineral from surface frost. This would have left behind a residual of excess OH-(ads) (relative to surface H+). Electrons were then stripped from the surface OH-(ads) (due to the large repulsive potential between neighboring OH-(ads)) and incorporated into the crystal to restore charge balance and produce a chemical reduction of the mineral. The resultant surface hydroxyl radicals could then have combined to form the more stable chemisorbed hydrogen peroxide species. While the chemisorbed peroxide should be relatively stable at low temperatures, it should tend to decay to O(ads)+ H2O(g) at higher temperatures with an activation energy of greater than or approximately 34 kcal mole-1. This is consistent with the long-term storage and sterilization behavior of the Viking soil oxidants. It is possible that as little as 0.1--1% frost-weathered material in the martian soil could have produced the unusual chemical activity that occurred during the Viking Gas Exchange and Labeled Release experiments.
[/b:post_uid0]

But that doesn't explain why olivine is present in a layer at the floor of Ganges Chasma. Maybe that layer has been revealed much later after the flood by wind erosion ?[/color:post_uid0]

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#50 2003-06-12 06:20:12

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Huge water ice reservoirs found on Mars!

[color=#000000:post_uid4]Thanks for the reply, Dickbill!
    Dealing first with the interesting extract in your last post, I feel, as you do, that it casts little light on the existence of olivine on, or near, the floor of Ganges Chasma.
    Rather, it seems to form part of the large body of research work carried out since Viking in order to find an explanation for the Gas Exchange and Labeled Release experimental data. Much of that research may be valid; Mars may indeed be totally sterile. As I've stated quite often, though, my view is that Mars almost certainly harbours life, at the very least in underground ecological niches. I base this assertion on the frequent exchange of crustal material which has occurred between Earth and Mars over geological time, which must certainly have resulted in the transfer of viable organisms in both directions. Even if every square centimetre of the surface of Mars today is subject to harsh oxidising and sterilising conditions, and I don't necessarily accept this as fact, there is little doubt in my mind that the deeper rock strata are host to a thriving community of organisms, most likely based on the same 20 amino acids as terrestrial organisms and using DNA as its blueprint.
    The only question we'll be left with, if all this is true, is which planet life actually originated on - Earth or Mars - and we may never find the answer to that one.

    Your idea that the olivine currently protruding from the bedrock deep in Ganges is the remnant of a much larger mineral body washed away by catastrophic flooding, doesn't help.  sad   Christensen states that the olivine is proof that the bedrock itself must also have been dry otherwise the olivine would have decomposed from contact with groundwater.
    Catastrophic flooding in the region would certainly have resulted in water seeping down into the sub-surface and probably remaining there long after the superficial water had evaporated. It seems to me that if the area has been subject to large-scale flooding on many occasions, the lower levels of Ganges would have been very wet for long periods - much too long, in fact, for any olivine to survive.

    It appears that this olivine's existence, at such a topographically low point on Mars, is a show-stopper for any notion of an Oceanus Borealis in Mars' past. Even a cursory glance at a contour map of the area shows clearly that, if Chryse and Acidalia were once part of an ocean, Ganges Chasma must necessarily have been inundated too!
    Conversely, if Ganges has never seen water, then neither have the northern Martian lowlands ever seen an ocean.
    The logic seems inescapable!    sad

    Anyone who can help me escape this inescapable logic is most welcome to show me how!

    Every time I think about it, I keep coming back to the olivine itself. There simply has to have been a mistake! Everything else points to a formerly wet Mars and current evidence points to an ocean of water trapped as ice just below the surface today. Olivine just can't exist at such a low point on such a watery planet!!     yikes

    This is [b:post_uid4]really[/b:post_uid4] weird.   ???[/color:post_uid4]


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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