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Fraser
2004-Mar-02, 07:23 PM
SUMMARY: NASA announced today that liquid water once soaked the environment around Opportunity's landing site, raising the chances that life once existed on the Red Planet. This announcement came from Opportunity's detailed examination of a region of exposed rock on the side of the crater it landed in. By analyzing the rock with every instrument at its disposal, scientists now have conclusive evidence that liquid water once acted on this rock, changing its texture and chemistry. Opportunity's next job will be to determine if the rocky outcrop was actually formed by water, or if it's volcanic in origin. This means that there was probably a long period of time on Mars where the environment would have supported life.

What do you think about this story? Post your comments below.

John LaCour
2004-Mar-02, 09:26 PM
This alone will do wonders for the Bush space vision of sending a man to Mars. Not only do we know there is available water at the Mars south pole, but we know there has been water on Mars throughout its past now. With the orbiters, landers, and sample return missions in the works, we should have enough information in 15 years to pick the best locations to land people to do the highly detailed, long-term exploration and analysis to answer to big questions.

For me the most important one is whether Mars even had life. If the answer is a definitive NO, then I see no reason why we shouldn't work to introduce it. Since we wouldn't be encroaching in a unique biosphere, we would be free to do whatever we wanted to Mars with a clean conscience.

om@umr.edu
2004-Mar-02, 10:30 PM
Great news, Fraser! :D

The past presence of life on Mars will be of interest to many, but I want to know why there is no liquid water on Mars now? <_<

Has the amount of solar radiation reaching Mars decreased over geologic time? :unsure:

In other words, does this finding tell us something about long-term climate trends for the terrestrial plantes? :blink:

With kind regards,

Oliver :D
http://www.umr.edu/~om

John LaCour
2004-Mar-02, 11:23 PM
The explanation I have heard for the lack of water on Mars today is because of its lack of a thick atmosphere. Mars lacks a global magnetic filed, which would have protected it from direct impact by the solar wind. Over the last few billion years, the solar wind has eroded the atmosphere of Mars to the current level of only 1% the air pressure on Earth. Water cannot exist in a liquid form in that low pressure and in the normal low temperatures that exist on Mars. In the rocks and under the polar caps it is only in solid ice form, but on the surface it would evaporate into the low pressure atmosphere.

Now, because Mars has such a thin atmosphere, and no protecting magnetic field, solar radiation in the form of UV and X-rays can reach the surface of the planet, and these will break apart water molecules into hydrogen and oxygen. The hydrogen is very light and can escape the atmosphere into space, as it does on Earth as well, while the oxygen combines with the iron in the soil to form the rust red color of the surface.

That&#39;s the story I&#39;ve heard, at least, as to why Mars has such a thin atmosphere with almost no water.

Victoria
2004-Mar-03, 02:08 AM
It would be great to see some sort of fossilization. Though the finds for today are super. :)

damienpaul
2004-Mar-03, 07:24 AM
This is indeed great news, finally some evidence of the anceinet water ways of mars, is it possible to get a conceptual map of a mars with water?

newc
2004-Mar-03, 09:12 AM
It is surely great news what NASA just announced.
Personally I still believe that some sort of liqiud can still flow on mar&#39;s surface (my guess is that it takes the right concentration of mud, salt, and water and the 1/10th of earth&#39;s pressure will be sufficent to avoid sublimation).
Anyhow, regardless of the possible presence of liquids on the surface what makes the announcement even more intresting is the fact that it implies the presence of water underground, in a salt-rich environment, at temperatures similar to those of our poles... I don&#39;t think it will take long to find what we all suspect: life isn&#39;t a unique feature of earth.

Guest_madaboutyou
2004-Mar-03, 04:30 PM
Wonderful, we are again a step closer to answering the biggy. But again my sincere mind has a problem with this finding. Once we have determined weather life does exist on mars (I mean when we find life cos&#39; people will keep lookin till the very end- some people just can&#39;t except things), the end product will never be as thrilling as the journey there. It&#39;s like soap operas, a couple are madly in love and the whole program focuses on them, they have a lovely white wedding, the magazines go mad... and then 1 week later the public would have forgotten who Kat and alfi are.
Anyhow, the point is enjoy the chase because as soon as we find life, all the excitement will disappear.

Victoria
2004-Mar-03, 05:11 PM
I had to step outside to fully gain reason on why an event so spectacular would be forgotten so nonchalantly <_< . Couldn&#39;t come up with much. :) I foresee a turn-around in appreciation for the stars. I know the demand is high for expectations these days...but I think this mission has already accomplished a major hope for future exploration and discovery. B)

om@umr.edu
2004-Mar-03, 06:01 PM
Originally posted by Victoria@Mar 3 2004, 05:11 PM
I had to step outside to fully gain reason on why an event so spectacular would be forgotten so nonchalantly <_< . Couldn&#39;t come up with much. :) I foresee a turn-around in appreciation for the stars. I know the demand is high for expectations these days...but I think this mission has already accomplished a major hope for future exploration and discovery. B)
You are right, Victoria, the discovery of evidence of water on Mars will not be nonchalantly forgotten. :D

I also agree that these results may signal a turn-around in appreciation for one particular star, the Sun. :rolleyes:

The Sun&#39;s radiant energy may be governed by the rate of neutron-emission from its core. If so, this likely decreased with time, following an exponential decay law similar for example to the decay of U-238. B)

This is discussed in two recent papers titled "The structure of the solar core" :unsure:

http://web.umr.edu/~om/abstracts2004/struc..._solar_core.pdf (http://web.umr.edu/~om/abstracts2004/structure_solar_core.pdf)

and “Is there a deficit of solar neutrinos?” :blink:

http://www.umr.edu/~om/abstracts2004/om-so...ar-neutrino.pdf (http://www.umr.edu/~om/abstracts2004/om-solar-neutrino.pdf)

Oliver :D
http://www.umr.edu/~om

Carson
2004-Mar-03, 06:30 PM
OPPORTUNITY FINDS CHOCOLATE ICE CREAM BAR WRAPPER ON MARS

Scientists were quick today to point out that chocolate ice cream bar wrappers do not necessarily indicate intelligent life on the frigid planet.

"To begin with," said Dr. Hoaxeasy of NASA, "my daughter eats a lot of ice cream bars, and she is not very intelligent at all."

It was also pointed out that ice cream bars were an especially dumb product to market in such a cold environment.

The theory that the Martian lander may have taken its own ice cream bar to Mars has been largely ruled out. "Again," Dr. Hoaxeasy is quoted as saying, "it would not be a wise choice of sustenance for an inanimate object like Opportunity to smuggle to Mars. We like to believe our lander has more intelligence than to equip itself with an ice cream bar."

Meanwhile, in Washington, the Bush administration proposes to bomb Mars, the landing site, and Opportunity. "We bomb everybody and everything we don&#39;t understand," George explained, "and that keeps us busy. This won&#39;t be the first good Opportunity we&#39;ve blasted to bits."

In NASA, things are very quiet, while investigators determine which influential space engineers prefer chocolate to vanilla or neapolitan.

As well, sociologists have pointed out the Martians may have become extinct. "It all indicates they were wasteful and didn&#39;t clean up after themselves," the esteemed People&#39;R&#39;Us Institute has said. "and that, together with the consumption of a frozen sugar product, indicates a society little able to sustain itself for long. If we find a cigarette butt, our evidence will be conclusive."

Other questions remain unresolved, however. The size of the ice cream bar wrapper--Opportunity has measured it as 31.5 meters in length--and also the apparent shadow which seems to have darkened recent photographs beamed back from the lander, have given rise to a certain amount of careless speculation.

All that NASA will officially say is that the distant planet does appear to have quite recently had deposits of water and dairy products extremely close to its surface, but that these findings in themselves do not conclusively point to anything very much in particular.

Duane
2004-Mar-03, 09:21 PM
Har har Carson&#33; :P

On Mars&#39; atmosphere, replying to John LaCour, I have been doing some reasearch into the state of the martian atmosphere and theories for how is has gotten to be the way that it is. I started my queries because of comments made in other threads, including one where I said the cause is the same as you have outlined here.

This was the leading theory until recently, and certainly was when I was in university.

Imagine my surprise when I found out the theory is now considered incorrect, at least as far as a single explanation goes.

The process you are describing is called "sputtering". As you have said, it basically describes how atmospheric gasses from a planet can escape as a result of contact with solar radiation. This process occurs on all bodies, but the type and extent of the gasses lost is dependant on the mass of the body and the interaction of the electric fields. The mass of Mars is such that several important atmospheric constituants, namely H, H2, O, O2, CO, N and others, can be accelerated to escape velocity.

The problem is that, assuming the atmosphere was thick enough at one point to sustain liquid water at the surface, calculations by Lammer, Stumptner and Molina-Cuberos suggest that the atmosphere would have lost only ~1Bar to this process in the last 3.5 billion years. That would not be enough to leave the atmoshere at it&#39;s current level.

Instead, it is now postulated that the main cause of the lost atmosphere has to do with large impactors. (damn I have spent 20 minutes looking for the site where I found this info to cite it--sorry can&#39;t find it :( ) Basically the energy of the impactors would have blown the atmosphere away from a body as small as Mars, whereas Earth and Venus would have retained or recaptured the atmosphere "lifted" in this way.

As such, it is believed the impactor process is responsible for 50 to 90% of the atmospheric loss on Mars.

The remainder of the loss is the result of sputtering and a "reverse greenhouse" effect.

God I love the internet&#33; :D

JESMKS
2004-Mar-03, 09:27 PM
An oxygen atmosphere had to exist at one time on Mars to create it&#39;s red color. Without oxygen, the rocks and soil would look like those we found on the moon. Electrolysis, lasers, x-rays and photosynsisis seem to be the only way to split a water molecule and release oxygen. I can find no method where ultra violet light can split a molecule. An alternate hypotheses could be that the early atmosphere created by volcanic activity was composed of water vapor and carbon dioxide. The water vapor condensed and precipitation created large lakes or an ocean. Phytoplankton, which may exist everywhere in our galaxy, infested the lakes or ocean and consumed carbon dioxide and produced the oxygen atmosphere. Oxygen in this atmosphere was consumed in the oxidation of surface materials. In time, the water molecules in the atmosphere were lost into space leaving only the heavier carbon dioxide molecules. This process ultimately consumed most of the liquid water on Mars. I think one question our scientists should address is how for or did evolution advance beyond a one cell phytoplankton. Iv&#39;e been watching for lichens on the rocks, but haven&#39;t seen any. The rovers on Mars is one of the greatest sucesses of my long life.
Jack

Duane
2004-Mar-03, 10:20 PM
Hey Jack, haven&#39;t seen your name for a few days :)

Cosmic rays can impart enough energy to split the water molecule. Outgassing by volcanoes could also be responsible for the O & O2 present in the rocks. In fact, I suggest that outgassing is probably more responsible for the amount of O2 bound up in the rocks on Mars than any type of life.

Not to pee on your parade, but........

JESMKS
2004-Mar-04, 12:32 AM
They have never detected Free Oxygen (O2) in volcanic gases on earth, so I doubt that the volcanic gases from Martian volcanoes ever contained Free Oxygen. The color of Mars looks like the Outback of Australia as seen from space. This required a free oxygen atmosphere. Cosmic radiation (x-rays) can split water molecules and produce free oxygen. I believe that the oxygen atmosphere on earth was produced and is maintained by photosynthesis not cosmic rays, so photosyntheseis may have been the process that produced the oxygen atmosphere on Mars.
Jack

Algenon the mouse
2004-Mar-04, 02:28 AM
I think it is great&#33; I can hardly wait to see if they find evidence of ancient life from another kind of Mars.


speaking of volcanos...
hmmm Maybe the volanic eruption of Olympus Mons threw so much ash into the upper atmosphere that it blocked out the sun causing an iceage that Mars never fully recovered...sorry just speculating.

I still think that it is likely that the moon of Mars was ripped into two causing Mars to wobble on its axis destroying all life.

Victoria
2004-Mar-04, 02:51 AM
Hence a half-moon forever? I don&#39;t understand. <_<

om@umr.edu
2004-Mar-04, 03:08 AM
Originally posted by John LaCour@Mar 2 2004, 11:23 PM
The explanation I have heard for the lack of water on Mars today is because of its lack of a thick atmosphere. Mars lacks a global magnetic filed, which would have protected it from direct impact by the solar wind. Over the last few billion years, the solar wind has eroded the atmosphere of Mars to the current level of only 1% the air pressure on Earth. Water cannot exist in a liquid form in that low pressure and in the normal low temperatures that exist on Mars. In the rocks and under the polar caps it is only in solid ice form, but on the surface it would evaporate into the low pressure atmosphere.

Now, because Mars has such a thin atmosphere, and no protecting magnetic field, solar radiation in the form of UV and X-rays can reach the surface of the planet, and these will break apart water molecules into hydrogen and oxygen. The hydrogen is very light and can escape the atmosphere into space, as it does on Earth as well, while the oxygen combines with the iron in the soil to form the rust red color of the surface.

That&#39;s the story I&#39;ve heard, at least, as to why Mars has such a thin atmosphere with almost no water.
John, that is an interesting idea. :D

Is it also possible that the thin atmosphere on Mars means that only a small part of this planet released gases to form its atmosphere? :rolleyes:

The amounts of radiogenic He-4, Ar-40, Xe-136 and Xe-129 in the atmospheres of Mars, Earth and Venus suggest that only 1-2% of Mars, 17% of Earth, and 100% of Venus released gases to their atmospheres ["The noble gas record of the terrestrial planets", Geochemical Journal, vol. 15, pp. 245-267 (1981)]. <_<

Since this is in the order of increasing surface temperature and decreasing distance from the Sun, the conclusion seemed reasonable. ;)

What do you think?

With kind regards,

Oliver :D
http://www.umr.edu/~om

Faulkner
2004-Mar-04, 10:19 AM
"Drenched"... Does this mean the landing area was once an ocean floor, a lakebed, or a puddle?

Is there any more information on this yet?

And why the hush-hush lead-up to the press conference? I think everybody was anticipating some sort of biological discovery&#33;

VanderL
2004-Mar-04, 01:32 PM
I think everybody was anticipating some sort of biological discovery&#33;

Some most definitely were (are), maybe the build-up is still going on, but they don&#39;t want to make the "1996 mistake" again (Martian meteoritic nanobacteria).
And the Opportunity "bedrock" could still be a fossilised plesiosaur (that was transported to Mars because of the Chitxulub impact and crashing into Mars), or the Martian "eggs" could have hatched like errorist is hoping&#33;
Cheers.

damienpaul
2004-Mar-04, 09:23 PM
Or the Martians are using the rovers as golf buggies and are having an excellent game from behind the lenses.

When do folks think a fossil be discovered?

Guest
2004-Mar-05, 04:20 AM
If memory serves me, I believe photosynthesis is indeed the great oxygen source and maintainer on our planet, but is not the only one. I know very little about under-sea chemosynthesis, but I believe it is very important.

Interesting take in this discussion: there is a quiet inference that it is not life, but rather water, which is the more significant in our space explorations. There have been many theories suggested that basic elements of life are scattered throughout the universe, but don&#39;t generally have the catalysts available to amount to much.

I have always been intrigued with the idea that our planet may pass through clouds of various organisms, which then become quickly proliferating transient diseases here on earth: in other words, a given disease does not originate here and spread quickly from its point of origin; but, rather, our planet is momentarily "bathed" in the organism as we pass through a cloud of it in space.

I sounds very far-fetched. But it isn&#39;t, if some of your ideas about living organisms elsewhere in space are correct. Very interesting stuff.

Carson
2004-Mar-05, 04:22 AM
--Oops. That was me. Sorry; I forgot to log in.

Tiny
2004-Mar-05, 04:44 AM
This time 99/100 of the scientists agree with this article(even my teacher).... water do exist on Mars long time ago, but some how it dries... and what cause this :ph34r: ?

Faulkner
2004-Mar-05, 05:17 AM
Thermonuclear war&#33;

VanderL
2004-Mar-05, 06:18 PM
When do folks think a fossil be discovered?

Maybe we have been staring at them for some time, but it will take a manned mission (or a return mission) to make sure. Meantime we need a good hard look at all the possible mechanisms that would have robbed Mars of it&#39;s water and atmosphere; whatever happened to Mars can also happen to Earth.


Thermonuclear war&#33;

Ok, that&#39;s option 1, any others?

Cheers.

Victoria
2004-Mar-05, 08:21 PM
I believe it was Algernon who came up with volcanic eruption...

Duane
2004-Mar-05, 10:04 PM
Hmm, I thought my earlier answer in this same post would have been enough. As it obviously isn&#39;t, I&#39;ll review a few processes which are thought to contribute to the loss of atmosphere on Mars.

First of all, this Link (http://www.gps.caltech.edu/~rkopp/collegepapers/sputtering.pdf) is a research paper by Bob Kopp then at the University of Chicago which describes in some detail how atmosheric sputtering (a new better link) (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993mppf.procQ..21J) affects the Martian atmosphere. It is a fairly techinical journal and you need Adobe to read it.


Jean&#39;s escape process (http://scienceworld.wolfram.com/astronomy/JeansEscape.html) is similar to sputtering, except that it relates to the heating of the atmosphere by solar radiation. It postulates that the amount of energy arriving from the sun would have been enough to excite atoms of many important constituants of Mar&#39;s atmosphere to escape velocity, thereby "draining" the atmosphere of these elements.

Another process which seems to be important on Mars, and as was alluded to earlier in this post by Jack (JESMKS), is the absorbtion of atmosphere into rocks and soils of Mars. This process was studied by M.B. McElroy and Y.L. Yung in 1976. Their calculations suggested that this could be an important process especially for the removal of atmospheric oxygen (O, O2) and may also play an important role in the formation of carbonates. The carbonate theory was dependant on the amount of water that may have been on Mars, along with the amount of time any water stayed in liquid form on the surface.

It appears that the most important cause of atmospheric loss on Mars is due to impact induced atmosperic erosion (http://www.lpi.usra.edu/meetings/lpsc97/pdf/1807.PDF) as proposed by D.A. Brain and B.M. Jakosky of the University of Colorado, Boulder. Essentially, this theory suggests that large impacts on the martian surface could have been responsible for the removal of as much as 90% (though more probably ~60%) of the outgassed atmosphere on Mars.

Basically, large impacts would "explode" atmosphere away from Mars, and it&#39;s low mass would not be sufficient to recapture the lost atmosphere. As well, heating from the impact itself would also thermally excite atmospheric elements and molecules beyond Mars&#39; escape velocity.

Regarding free O & O2 on Mars, I agree with Jack&#39;s comment that free O2 would be unlikely to have arisen by itself only as a result of outgassing. This has to do with the reactiveness of oxygen to many other elements. Having said that, it seems reasonably certain that the outgassing of CO2, H2O, CO, CO3, SO2 and others would have been similar to that seen on the other terrestrial planets.

O2 also gets easily bound up in iron silicates, which are quite common on Mars.

CO2 remains the most common gas on Mars, by far. While this is a very stable molecule, Mars does not have the benefit of an extensive magnetic field to protect it from incoming cosmic rays. As a result, and over eons, the breakup of CO2 into CO & O may explain the build up of the O2 seen in the surface rocks and soil.

Furthermore, although O2 is not common in volcanic eruptions, it is not unknown.

R.A. Craddock and R. Greenly of Arizona State University suggest, in part, that a warmer atmospheric temperature and pressure arising from volcanic eruptions on Mars may have been enough to decouple the Jean&#39;s escape of H from the non-thermal escape of O2, which would also cause O2 to build up in the atmosphere.

So, to briefly sum up, the loss of atmosphere on Mars is the result of a number of processes, all of which contribute to a greater or lesser extent to the loss of atmosphere. The biggest common denominator is the small size of the planet.

VanderL
2004-Mar-05, 11:01 PM
Thanks Duane, but when exactly was Mars drenched in water, where is it now (gone or below surface, or into space?) and the processes that you mention, can they be measured and could they be used to calculate back to the "wet Mars epoch"?

I believe it was Algernon who came up with volcanic eruption...
Ok, that&#39;s 2, and who said that the impact that created some basin or other was responsible for the big volcanoes on the other side of Mars (in some other thread I think), or was that also Algernon?
Volcanoes on Earth release large amounts of water, can the volcanoes on Mars (they&#39;re big, but are they numerous enough?) be responsible for the "drenching"?

Cheers.

om@umr.edu
2004-Mar-05, 11:43 PM
Thanks, Duane, for pointing out processes which might have contributed to the loss of Mars&#39; atmosphere. :D

As mentioned earlier on this site, the inventory of radiogenic He-4, Ar-40, Xe-129 and Xe-136 the atmospheres of Mars, Earth, and Venus suggests that the portion of these planets that released volatiles into the atmosphere were:

1-2% for Mars, <_<
17% for Earth, ;) and
100% for Venus. :rolleyes:

Aside from the recent NASA report that Mars was drenched in water :unsure:, is there any reason to believe that Mars initially released volatiles as efficiently to its atmosphere as did the warmer planets closer to the Sun?

Oliver :D
http://www.umr.edu/~om

Victoria
2004-Mar-06, 01:55 AM
Since it&#39;s all up in the air for now, my menial question is why Fe is so prominant? Does it have to do with its density? Like salt in the body soaks up everything and makes one more thirsty although there is sufficient water to flow...all these com-ponents make one wonder what is hiding under the soil other than a pteradactyl. :P

Duane
2004-Mar-06, 02:30 AM
but when exactly was Mars drenched in water

This is not known for sure. Some investigations say it might be recent. The evidence suggests that the area around the Opportunity lander was once very wet. There is no discussion on how long that lasted, nor when it occurred. (not yet)


where is it now (gone or below surface, or into space?)

Judging by the evidence, it evaporated into space.


and the processes that you mention, can they be measured and could they be used to calculate back to the "wet Mars epoch"?


Yea, the &#036;64000 question. I would think it would require direct physical examination to say for sure.


Ok, that&#39;s 2,

No, thats six. Thermonuclear explosion, sputtering, Jean&#39;s escape, impact induced atmospheric erosion, atmospheric absorbtion, volcanic activity.


Volcanoes on Earth release large amounts of water, can the volcanoes on Mars (they&#39;re big, but are they numerous enough?) be responsible for the "drenching"?


Yes. Assuming the volcanoes released a similar amount and content of gasses per eruption as are evident on the other terrestrial planets.

I hope no one minds my use of quotes, it just makes answering the questions easier.

Oliver, I am a little confused with the way you&#39;ve worded your question. I&#39;m thinking about it, let me get back to you.

Algenon the mouse
2004-Mar-06, 03:51 AM
Although I mentioned the volcanic outgasing eariler I actually think that volcanos on Mars had only a little to do with the "dampness" of Mars. It Probably did have a thicker atmosphere which helped keep the planet moist. For Outgassing to help with moisture, You need a thick layered atmosphere.


As far as the loss of the atmosphere....It is quite possible that a huge meteor (planet?) hit Mars&#39; moon causing more meteors (pieces of the orginal )to hit mars. The impacts probably diminished the atmosphere and helped speed up the loss. The lack of a stable tilt and the size of Mars did not help either.

Victoria, the two moons Mars has left could have been one. It is one of the stronger theories.

btw it is Algenon. I drop the r because it does not fit in some slots for names.

Duane
2004-Mar-06, 09:34 AM
Although I mentioned the volcanic outgasing eariler I actually think that volcanos on Mars had only a little to do with the "dampness" of Mars.

Well, no. If Mars had a significant atmosphere, then it could only have gotten it from volcanic outgassng. There is simply no other means by which a planet the size of Mars could have developed an atmosphere thick enough to support liquid water.

Victoria
2004-Mar-06, 10:10 AM
The moons, the planets, the stars...I need to find myself a nice big pic to post on my wall to grasp a better understanding of it all. Not like I feel bad about having to get it, I hope you&#39;ll understand my density. When speaking of moons exploding and dividing with a few pieces creating more craters and eruptions below, how would the two moons rotate? I mean after that huge boom-all is quiet and peaceful? Not a half moon but two moons instead just floating up there for us to see? I am amazed. B)

VanderL
2004-Mar-06, 10:30 AM
Sorry Duane, I didn&#39;t read the whole thread, and sorry Algenon without the r. So it&#39;s six and what about the planetary collision theory, let&#39;s not discount that one. What was it again: "If it is impossible it didn&#39;t happen and if it happened it wasn&#39;t impossible". ;)


As mentioned earlier on this site, the inventory of radiogenic He-4, Ar-40, Xe-129 and Xe-136 the atmospheres of Mars, Earth, and Venus suggests that the portion of these planets that released volatiles into the atmosphere were:

1-2% for Mars, dry.gif
17% for Earth, wink.gif and
100% for Venus. rolleyes.gif

Oliver, these percentages, what are they compared to and how can these numbers be significant if we don&#39;t know the contents of the inner parts of the planets that release them, or even if they were released at all?

Cheers.

om@umr.edu
2004-Mar-06, 02:22 PM
Great question&#33; :D

"these percentages, what are they compared to and how can these numbers be significant if we don&#39;t know the contents of the inner parts of the planets that release them"? <_<

Non-volatile radioactive elements that decayed inside planets (K, I, U, Th, Pu) into gaseous daughter products (Ar, Xe, He) tell us the percent of the planet that released volatiles to its atmosphere. :)

Our 1971 paper in Science showed, for example, that degassing of Earth to form its atmosphere definitely ceased before all of the I-129 (half-life = 16 My) and Pu-244 (half-life = 82 My) decayed. :rolleyes:

[Sorry, references are on my web site, but pdf files for older papers are not yet there, http://www.umr.edu/~om ]. :unsure:

Our paper in Geochemical Journal a decade later used measurements of the amount of gaseous decay products in the atmospheres and an assumption that

i) the initial inventories of K, I, U, Th, and Pu in the planetary mantles were like those in chondritic meteorites, and

ii) the initial inventories of K, I, U, Th, and Pu in the cores like those in iron meteorites

to calculate the percentages of radiogenic gases released to the atmospheres. <_<

With kind regards,

Oliver :D

Nick4
2004-Mar-06, 03:54 PM
Do you think we could find fossal life?

om@umr.edu
2004-Mar-07, 01:17 AM
Originally posted by Nick4@Mar 6 2004, 03:54 PM
Do you think we could find fossil life?
That depends, Nick, on several things we do not yet know. :D

For example,

i) How much liquid water once existed on the Martian surface? :huh:

ii) How long was it there? <_<

iii) What was the surface temperature at that time? :unsure:

The discovery of fossils on Mars would exciting&#33; :D

Of greater concern for our future would be the finding of a record on the Martian surface of long-term climate trends for the terrestrial planets, especially climate changes induced by changes in solar radiation. B)

With kind regards,

Oliver :rolleyes:

Victoria
2004-Mar-07, 04:27 AM
Now we&#39;re diggin B) , sort of like the shrine built inside Mt. Rushmore? Or the discovery of King Tut&#39;s tomb. :)

Algenon the mouse
2004-Mar-07, 10:32 PM
Originally posted by Duane@Mar 6 2004, 09:34 AM

Although I mentioned the volcanic outgasing eariler I actually think that volcanos on Mars had only a little to do with the "dampness" of Mars.

Well, no. If Mars had a significant atmosphere, then it could only have gotten it from volcanic outgassng. There is simply no other means by which a planet the size of Mars could have developed an atmosphere thick enough to support liquid water.
You are thinking a bit more in the eariler history of Mars than I am. I was referring to a more recent volcanic eruption blocking a zone of the atmosphere like the stratosphere of earth, therefore relfecting the sun rays off the tropsphere(sp?) where weather takes place and causing a cooler climate, possibly more precipiataion. It is harder for something like this to occur if the atmosphere was not thick to begin with.

Duane
2004-Mar-08, 07:10 PM
Oliver, as promised, I have spent some time researching in an attempt to anwer the questions you posed.

With regard to the possibility that Mars released volitiles as efficiently as the other terrestrial planets (excluding Mercury of course) H.H. Kieffer et al at the University of Arizona suggested that their analysis of Martian meteorites found a much higher volitile inventory appears to have been present on Mars in its early history (the Nochian epoche >3.5Bya). A large portion (~99%) of this early atmosphere appears to have been lost by the end of the heavy bombardment period ~3.8Bya.

This analysis suggests that the very early Martian atmosphere was the result of the release of volitiles as part of the outgassing occurring during the formation of the Tharsis region (and others), which dates to roughly the same epoche (3.6Bya - 4.0Bya).

Crater deformation and overlying erosional material of the Nochian landforms suggests that most fluidal erosional activity on Mars had mostly ended by the Hesperian-Amazonian boundry, estimated to be around 2.9-3.3Bya (Hartmann & Newkum, 2001). As such, it is suggested that any significant Martian atmosphere had larely disappeared by that time. Since then, it appears that any further fluidal erosion has been episodic in nature.

Interestingly, such episodic fluidic activity may be the result of episodic volcanic activity (Dr Karl Mitchell et al, University of Lancaster and others) which suggests, amoung other things, that volcanic activity may have been possible only a few millions of years ago.

Assuming that the atmosphere necessary to support liquid water was present during the Nochian epoche, the I suggest that the initial release of volitiles must have been fairly efficient. Having said that, I am not able to find any research that suggests that the release of volitiles was as effiecient as that seen on the other terrestrial planets.

Regarding your findings on the portions of released volitiles on the terrestrial planets (again, excluding Mercury) is it possible that percentages you have found relate to the different methods thought responsible for the cooling of the planets&#39; cores?

As I understand it, Venus uses a method of internal heat release related to a form of lithospheric overturn, Earth uses plate tectonics, and Mars used a combination of thermal release and shield volcanic activity. As the interior of Mars appears to have cooled ~3.5Bya, whereas Earth & Venus appear to be currently active, could this account for the differential release of volitiles?

om@umr.edu
2004-Mar-09, 06:04 AM
Thanks, Duane, for the time and effort you devoted to reviewing literature on the release of volatiles to the Martian atmosphere. :D

Before commenting on your report, let me review some of the puzzling observations made on the release of volatiles to the Earth&#39;s atmosphere. The Earth is much more accessible for study, but it took us decades to decipher these observations: <_<

1. The Earth&#39;s upper mantle obviously released volatiles exhaustively, very early, within the first 200 My, when it differentiated to form the crust. We know that because the decay products of extinct I-129 and Pu-244 (Xe-129 and Xe-136) accumulated in the upper mantle after this event. :rolleyes:

2. But the Earth&#39;s lower mantle remained primitive and undifferentiated. (Puzzle #1: How could the Earth form an iron core surrounded by an undifferentiated lower mantle?) :huh:

3. The Earth&#39;s upper mantle exaustively released its Ar too. Thus extremely high enrichments of radiogenic Ar-40 are observed there today. ;)

4. However most of the radiogenic Ar-40 in air came from the crust, which continued to release this decay product of K-40 until about 2 Gy ago. :)

5. Presently gases from the upper mantle in MORB (Mid-Ocean Ridge Basalts) and in carbon dioxide gases contain large enrichments of radiogenic Ar-40, Xe-129 and Xe-136 - - - as expected if the upper mantle was exhaustively degassed in the first 200 My. :rolleyes: But these are accompanied by primordial (non-radiogenic) He-3. (Puzzle #2: Why do we see primordial He-3 accompanying radiogenic Ar and Xe?) :unsure:

These puzzling results were finally deciphered in 1981 ["The noble gas record of the terrestrial planets", Geochemical Journal, vol. 15, pages 245-267]. :D

Answer to Puzzle #1: The Earth accreted heterogeneously. Its iron core grew first out of material like iron meteorites. This iron object then served as the accretion site on which the silicate mantle accreted from material like stone meteorites. ;)

Answer to Puzzle #2: Only the upper mantle exhaustively released volatiles to form the atmosphere. But Helium is highly mobile. Thus, it continues to leak out of the primitive, undifferentiated lower mantle. This primordial He-3 passes through the upper mantle, which is laden with radiogenic Ar-40, Xe-129 and Xe-136, and we see this mixture at the top of the upper mantle today. ;)

There is simply no way we could have solved these puzzles from pictures of the planet&#39;s surface and analyses on a few pieces of material knocked off the surface by impacts like those that created Martian meteorites. :blink:

A piece knocked from the Earth&#39;s crust, upper mantle, or lower mantle would contain radically different concentrations of volatile elements and dissimilar enrichments of radiogenic gases. :huh:

With kind regards,

Oliver :D
http://umr.edu/~om

Duane
2004-Mar-09, 06:51 PM
Wow, this is really interesting :o

Okay, so if I am following you, that seems to support the findings of Kieffler et al, in that the trapped gases in the Martian meteorite only confirms that the early Martian atmosphere could have contained such volitiles, but that may only be indicative of the early outgased atmospheric history of Mars? :huh:

I assume that the modelling from meteorites that you used to decipher the percentages of volitiles outgassed by the other terrestrial planets was also dependant on the current makeup of the atmospheres? :blink:

Again, assuming I am following you, the different means by which the planets release internal heat would seem to support my comment; that is, that the different methods would lead to the different percentages. Right?

I am wondering how your findings correlate to the proposed impact of a Mars-sized body with the proto-earth, which created the earth-moon system?:huh: If such a large impact occurred, how could the lower mantle have escaped strong differentation?

Duane
2004-Mar-12, 07:27 AM
Thought I would bring this up front again. I am really interested in this, and would like to read the answer :)

om@umr.edu
2004-Mar-12, 08:18 PM
Thanks, Duane, for your comments on the discussions:

1. “Water Once Drenched Regions of Mars"

2. “Spitzer Looks at a Stellar Nursary"
http://www.universetoday.com/forum/index.p...view=getnewpost (http://www.universetoday.com/forum/index.php?showtopic=2435&view=getnewpost)

Measurements over the past four decades show that these two seemingly unrelated topics are, in fact, closely related:

The Earth and the Sun both formed in layers of different composition (heterogeneous accretion).

1. The Earth first formed an iron core by accreting iron-rich material produced near the core of a supernova. This collection of iron-meteorite-like material then acted as the accretion site for silicates (stone meteorites) that formed further away from the Sun. The most concise summary of these observations is given in “The noble gas record of the terrestrial planets”, Geochemical Journal, volume 15, pp. 245-267 (1981). [Since a pdf or ps file of this manuscript is not yet available, pertinent observations are summarized below*.] ADDED 06/12/2004

http://web.umr.edu/~om/archive/NobleGas.pdf

2. The Sun grew as supernova debris fell back on the collapsed supernova core (a neutron star). The most concise summary of these observations is given in "Composition of the Solar Interior: Information from Isotope Ratios", Proceedings of the SOHO 12 / GONG+ 2002 Conference: Local and Global Helioseismology (ed: Huguette Lacoste, ESA Publications Division, SP-517, Noordwijk, The Netherlands, Feb 2003) pages 345-348.
http://www.umr.edu/~om/abstracts2002/soho-gong2002.pdf
http://www.umr.edu/~om/abstracts2002/soho-gong2002.ps

The first set of observations may eventually be included in textbooks on Geology. Likewise, the second set of observations may later be included in textbooks on Astronomy/Astrophysics.

Although observations in research publications may be “beyond what a ‘backyard’ astronomer can really answer”, Duane, you and I will be talking past each other and wasting readers’ time if you refer to textbooks to buttress your arguments instead of addressing recent findings.

To avoid this,click on the pdf or ps file of the ""Composition of the Solar Interior: Information from Isotope Ratios" and address the observations. (The answers will not be in textbooks):

http://www.umr.edu/~om/abstracts2002/soho-gong2002.pdf
http://www.umr.edu/~om/abstracts2002/soho-gong2002.ps

1. Why were there two distinct types of xenon, Xe-1 and Xe-2, at the birth of the solar system [Figure 1]?

2. Why did primordial Helium accompany Xe-2 (strange xenon) and not Xe-1 (normal xenon) when meteorites formed [Figure 2]?

3. Why does the Jupiter’s He-rich atmosphere contain Xe-2 (strange xenon) (p. 346)?
http://www.umr.edu/~om/abstracts2001/windl...leranalysis.pdf (http://www.umr.edu/~om/abstracts2001/windleranalysis.pdf)

4. Why are light mass (L) isotopes in the solar wind enriched relative to heavy mass (H) isotopes by a common fractionation factor (f), where log (f) = 4.56 log (H/L) [This is shown in Figure 5 and discussed on pp. 346-347.]?

5. When the above empirical equation is applied to elements in the photosphere, why does it indicate that the interior of the Sun consists mostly of Fe, O, Si, Ni, S, Mg and Ca, the same elements as that comprise 99% of ordinary meteorites (p. 347)?

6. The statistical probability that this agreement is fortuitous is <0.000000000000000000000000000000002 &#33;&#33; How do you explain that?

7. More recent evidence that mass separation enriches lightweight elements in the photosphere is shown in 4 Figures and a Conclusion on the upper right side of my updated web page

http://www.umr.edu/~om
* Fig 1. Sun&#39;s Surface Composition
* Fig 2. Solar Mass Separation
* Fig 3. Composition of Bulk Sun
* Fig 4. Composition of Bulk Sun
* Why the Model of a Hydrogen-Filled Sun Is Obsolete

As mentioned before, about 17% of the Earth released gases to the atmosphere. The Moon is only about 1% of the mass of the Earth. You may also want to consider other pertinent observations on the evolution of the Earth’s atmosphere listed below.

I look forward to your replies.

With kind regards,

Oliver :D
http://www.umr.edu/~om

PS - The Geochemistry Division of NSF funded our study of the “Early History of the Earth and the Evolution of Its Atmosphere.”

http://web.umr.edu/~om/archive/NobleGas.pdf

Our measurements and those of others showed that:

1. The upper mantle melted to form the crust and release volatiles exhaustively to the atmosphere in the first 200 My, before extinct I-129 and Pu-244 decayed away.

2. The crust continued to release radiogenic gases to the atmosphere for 2,500 My.

3. The lower mantle surrounding the Earth’s iron core did not melt. It remained primitive and undifferentialed. It retains all but the most mobile volatile elements.

4. Helium is very mobile. That is why primordial He-3 leaking from the lower mantle is now found with radiogenic Ar-40, xenon-129, and xenon-136 from the upper mantle in mid-ocean ridge basalts (MORB) and carbon dioxide well gas.

Mike Martin
2004-Mar-24, 08:48 PM
I&#39;ve been very interested in Mars lately. As a Christian, findings there will directly affect my faith.
We at Modern Disciple Magazine are interested in any input you may have. Visit our discussion pages at: http://www.moderndisciplemag.com/discussion.asp

Thank you

om@umr.edu
2004-Mar-24, 09:05 PM
Mike, I am convinced science and spirituality do not conflict. However, that is not to say that scientific results may not occassionally seem to conflict with a particular religious dogma.

Best wishes,

Oliver

antoniseb
2004-Mar-25, 01:12 PM
Originally posted by Mike Martin@Mar 24 2004, 08:48 PM
I&#39;ve been very interested in Mars lately. As a Christian, findings there will directly affect my faith.
Mike&#39;s faith won&#39;t be affected by the discovery of Life on Mars if it ever happens. The above message was bait to encourage non-creationists to come to his forum. I suggest before posting to his forum [if you are so inclined] that you read the creation vs evolution thread on his forum. It will give you a sense of the kind of discussion you are in for, and the likelyhood that you might successfully get your point across.