H20, where'd it go? - What happened to Marsian water?

Palomar · 2003-09-06 07:18:05

*I also posted another (related) article before this one.

--Cindy

Shaun Barrett · 2003-09-07 06:42:54

Thanks for the link to the "Rusting Mars Without Water" article, Cindy.

As I mentioned when I posted about iron oxide on Mars, I knew there were other ways for all that oxide to form besides water. But my emphasis was really on the fact that large amounts of free oxygen in the presence of water here on Earth were responsible for the red bands of iron oxide in ocean sediments, and that it seems the easiest way for large amounts of the compund to form.
In another version of the article you linked, I seem to remember reading that Albert Yen was still of the opinion that Mars had been awash with water, at least episodically. He pointed to the topographical evidence for this while offering the meteoritic iron explanation, without water, simply as a possible alternative. Christensen's olivine and low levels of carbonate discovered so far are no doubt the very understandable underlying reasons for seeking a 'dry option' for so much rust. And the dry option may well prove correct, though my present opinion is it that it probably won't.

You have to take the article with a pinch of salt, too, when you consider the language in which it's couched. It really is very speculative and full of 'ifs', 'buts' and 'maybes'. Mull over these excerpts (and my comments) to get a feel for the tentative nature of the conclusions reached:-

"The idea isn't far-fetched." (It shouldn't be necessary to state this! )

"... 20 to 60 tons of meteoritic debris falls on Mars every year. Over a billion years this would make a global layer up to 5 centimeters thick, if it all stayed on the surface."
"... an atom of meteoritic iron releases an electron when hit with ultraviolet radiation." (How much of the 20 to 60 tons of material is the iron-rich variety and how much is the iron-poor stony or carbonaceous variety? Is the 5cm layer all dust? What of larger lumps of meteorite where only the surface layer is exposed to UV light? What proportion of this alleged iron-rich debris has been covered over by lava flows, even in the last billion years? And even if none is covered by volcanic activity, 5cms per billion years gives us maybe 20cms for all of Martian history, i.e. about 8 inches! By the time the winds have blown much of this into drifts and dunes many metres deep, is there really enough left to make the whole planet look red, even from Earth? I have my doubts.)

"If that electron is captured by oxygen in the Martian atmosphere before it can return to its source, the iron atom becomes oxidised, or rusted." (No indication is given of how likely it is that the freed electron will find an oxygen atom in the air. In Martian air today, the chances must be high that the iron would regain its electron before losing it permanently because there is so little free oxygen. Is Dr. Yen proposing that Mars had a significantly higher atmospheric O2 concentration in the past? If so, how was this higher concentration maintained, against the natural energy gradient or entropy, for billions of years, without some mechanism to replenish it? And, if oxygen were more plentiful, for whatever reason, some of it would form an ozone shield against the very UV light crucial to his hypothesis, thus reducing the rate of 'dry' oxidation anyway! )

"As additional circumstantial evidence, the crusts of meteorites that fall to Earth are magnetic; so is Martian dirt." (This implies that the major portion of a terrestrial meteorite, its interior, is not magnetised. This fits in with the fact that only the outer surface of a meteorite becomes molten through friction with the atmosphere, while the interior can remain extremely cold. Thus, the crust acquires the strong imprint of Earth's powerful global magnetic field while it's molten, just like lava. Remember though, that the majority of the meteorite, even here on Earth, isn't magnetised. But Mars doesn't have a magnetic field! Conventional wisdom says it hasn't had one for maybe 4 billion years! So what proportion of Martian meteoritic debris should we expect to be magnetised? I would suggest precious little. In other words, this so-called 'additional circumstantial evidence' appears to weaken rather than strengthen Yen's case.)

This kind of article seems to me indicative of the high degree of confusion among scientists today regarding Mars. The whole place is a conundrum and there's no single coherent hypothesis which even comes close to reconciling the infuriatingly contradictory evidence we've gathered. For every scientist with a scenario to explain why Mars is the way it is, there's another scientist who can prove the scenario wrong!!
What fun!

rgcarnes · 2003-09-07 16:41:53

Shawn and...,

It seems that as long as we (humanity) continues to be effectively glued to this planet by various forms of political and social dissipation, rather than "Boldly Going Where...", that we are taking a parallel path to the ancient Greek philosophers who, having slaves to do their everyday work, spent their time arguing philosophical questions without doing the requisite definitive experiments to try to find out the truth.

From my point of view, the recent Arkansas Mars environmental simulation experiments are a step in the right direction, lets press on to actually getting there so we can begin to recognize the specious philosophies from reality in a definitive way.

Wouldn't it be a benefit to humanity to be able to differentiate and weed out the highly paid con artists from the appropriately compensated scientists so that they can learn to make an honest living? That, perhaps idealistic, goal alone should make the price of our expeditions to Mars well worth the initial sacrifice.

alokmohan · 2003-10-01 04:55:54

Even thogh the post is old the topic is relevant.

jkosar · 2004-02-05 19:39:43

The Mars orbiters, both American and EU have shown water on Mars, yet the People at NASA, that control the ground based Rovers, keep saying that they are looking for past evidence of water on the Martian surface. If there is supposedly water with in a few feet of the surface, why don"t they just dig a hole and analyze the material. They keep looking for minerals and rocks that prove water once existed. If we are ever to go to Mars we need to know where the water is and how much. You cannot drive rocket engines with rocks.

Byron · 2004-02-06 06:57:54

The Mars orbiters, both American and EU have shown water on Mars, yet the People at NASA, that control the ground based Rovers, keep saying that they are looking for past evidence of water on the Martian surface. If there is supposedly water with in a few feet of the surface, why don"t they just dig a hole and analyze the material. They keep looking for minerals and rocks that prove water once existed. If we are ever to go to Mars we need to know where the water is and how much. You cannot drive rocket engines with rocks.

But that would make too much sense to do something as obvious as that...lol. I'd like to see them drop a bulldozer on Mars and dig a hole about 20 meters deep and see what we find. Just imagine what we'd find....

B

dickbill · 2004-02-06 07:16:59

The Mars orbiters, both American and EU have shown water on Mars, yet the People at NASA, that control the ground based Rovers, keep saying that they are looking for past evidence of water on the Martian surface. If there is supposedly water with in a few feet of the surface, why don"t they just dig a hole and analyze the material. They keep looking for minerals and rocks that prove water once existed. If we are ever to go to Mars we need to know where the water is and how much. You cannot drive rocket engines with rocks.

The issue is to demonstrate that water, liquid, was present at the SURFACE of MArs in the past, not just to show that water present.
For how long and in what amount did that liquid water flood on the Martian surface, that's a first question.
Did lake persisted
Was an ocean there ?
The issue of how long was liquid water there is the most important IMO.

Earthfirst · 2004-02-10 21:14:28

I think that there was an ocean on mars, a billion years of sifting sand dune could of easly covered up the evidense.
Once there are people or robots that can drill down into the permafrost and see how deep it is we wont know. But just look at the north polar cap it is almost all water, to me it looks like it is the size of the greenland cap on earth. If that was to melt it could easly form a small sea. The big question is how much water is in the permiforst at near the equater, thats were the frist water will melt during terriforming. I think that there is lots of water in the big canyon.
Even on the earth theres lots of peraforst that never melts, so to release all of mars water to form a ocean the green house effect would have to be greater than on the earth.
So we would first have to realy bake mars before we would have an ocean.

DonPanic · 2004-02-13 06:15:38

LO

I think that there was an ocean on mars, a billion years of sifting sand dune could of easly covered up the evidense.

Ocean should sculpt clifts, not so easily hidden by sand dunes
is there some evidences of sea digged clifts ?

Earthfirst · 2004-02-13 10:28:33

Yes there would be cliffs, sea caves, and beaches. But the oceans on mars might not have been around long enough to make such landforms visable from space. Theres all ready evidense for large flows of water on mars, rivers, lakes, some of those lakes could be as large as seas.

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#76 2003-09-06 07:18:05

Re: H20, where'd it go? - What happened to Marsian water?

#77 2003-09-07 06:42:54

Re: H20, where'd it go? - What happened to Marsian water?

#78 2003-09-07 16:41:53

Re: H20, where'd it go? - What happened to Marsian water?

#79 2003-10-01 04:55:54

Re: H20, where'd it go? - What happened to Marsian water?

#80 2004-02-05 19:39:43

Re: H20, where'd it go? - What happened to Marsian water?

#81 2004-02-06 06:57:54

Re: H20, where'd it go? - What happened to Marsian water?

#82 2004-02-06 07:16:59

Re: H20, where'd it go? - What happened to Marsian water?

#83 2004-02-10 21:14:28

Re: H20, where'd it go? - What happened to Marsian water?

#84 2004-02-13 06:15:38

Re: H20, where'd it go? - What happened to Marsian water?

#85 2004-02-13 10:28:33

Re: H20, where'd it go? - What happened to Marsian water?

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