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Mars May Be Dry After All
BillC writes "Boston Globe reports that all the Martian features which looked like water just under the surface might merely be the land features left behind when glaciers retreated thousands or millions of years ago."
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Actually, most scientists believe that the majority of Mars's atmosphere and water vanished into space. Mars has less mass than Earth, which also implies a lower gravitational pull. It turns out that the solar wind (as well as convection) is enough to sheer away critical molecules from the atmosphere.
So water would evaporate, and maybe 0.005% of it was blasted away by the solar wind. Give it a few million years and you're left with a very thin atmosphere and no water. Consquently, this is also why the moon cannot support an atmosphere. It's also why if anyone tells you they can totally teraform Mars into another Earth, they're lying.
Another poster has answered your question about how Mars loses water. No magnetic field -> dissociation of water into hydrogen -> lose hydrogen to space.
:)
Perhaps the question should really be: How is it that Earth came to have so much water? Last I heard, scientists were still arguing about this, but cometary impacts are one likely source. In addition, it would seem that the Earth's magnetic field helps protect what water we have (in contrast with Mars).
We live on one lucky planet
Is this the promised end? Or image of that horror? KING LEAR
It did have water, and does have water now. In fact, it has polar ice caps, I believe. The issue is whether it has liquid water, as wherever we have found liquid water, we have found life.
Scientists have found lots of lifeforms in our extreme environments (they're called extremophiles). We've found life in the coldest of the cold, and in volcanic activities (both land-based and ocean-based). However, there's no rule that says that water == life, or that water can't exist without life.
Although, I don't know what spending billions of dollars to find a few space microbes will accomplish.
So you're saying Mars is a big ball of rust?
According to my astronomy teacher, the core of Mars cooled off and solidified, eliminating the magnetic field. You need circulating currents of material in the core to produce a magnetic field. Another problem associated with a low mass planet.
First off, the article is based on unpublished information. It sounded like the Boston Globe was basing its information on a talk given at a seminar that consisted of one persons opinion based on anecdotal evidence. Definately not something strong enough at this point to refute the theories currently being bandied about.
The text you are quoting came from the article's description of how similar features formed on Devon Island in Canada. The explaination for Mars is that a very long time ago, it was warm enough and the atmosphere was thick enough for liquid water and that was when the snow fell to them help form the features in question.
It would seem that they have overlooked a key fact. Scientists that study the geology of other planets and moons have developed models that allow them to determine how old a surface feature is based on how many impact craters the feature has. The more craters in evidence, the older the feature. This model has been used on all the objects in the solar system, Mercury, Luna, Io, Europa, Venus, Ganymede, asteroids, etc. What Mr. Malin found was that the drainage features were relatively undisturbed which indicates relative youth, say anywhere between 100 and 10,000 years old. If the formation of snow in the amounts the article mentioned could not have extisted in the last 100,000 years, it would seem to contradict his theory.
The article also mentioned glaciers and I can not resist mentioning that as far as I know, nobody has ever claimed that glaciers have formed for any length of time on Mars. Glaciers form by the collection of snow over long periods of time which requires an atmosphere thick enough to support precipitation. The evidence so far seems to support a relatively short period of flooding billions of years ago and relative dryness since then. Once a glacier formed, it would have existed for a very long time in the cold air of Mars. On one hand, if it sublimated like CO2 (which H2O doesn't do, of course) and that was why they don't exist anymore, they would have shielded the landscape from impacts and that alone would have already shown up in the images Surveyor has sent back. On the other hand, if the glacier melted, it would have melted relatively slowly and again, there would be evidence of this of which none exists.
Last but not least is one small matter. The features in question have formed on the inside wall of an impact crator. It would seem very unlikely that this would be where a glacier could form. As to areas of snow, because of the age of the features, any snow would have had to have fallen since the crator formed, which isn't supported by the impact record.
SUMMARY:
The Boston Globe needs a better Science editor.
Anyone care to comment on my reasoning or facts?
We the Sheeple...
Smaller planets, such as Mars, have less mass and a weaker gravitational field, reducing the escape velocity. This allows gases to escape the planet's atmosphere into outer space. There is a statistical description of the velocity of gas molecules, I've forgotten the name, that allows you to predict the velocities of gas molecules at a given temperature and pressure. If a gas molecule in the upper atmosphere is going fast enough, and in the right direction, it will escape from the planet.
"Millions of disgusted viewers report that all the narrative features which looked like talent or good plot just under the surface might merely be the crap left behind when hollywood writing talent retreated thousands or millions of years ago."
um, hello? Unless we're talking about frozen methane or some other weirdness, glaciers = water.
Using your sig line to advertise for friends is lame.
My local Wal-Mart is selling a product called Martian Mud. Since one half of the recipe calls for water (I'm assuming Martian water), there is no doubt that Mars has an ample supply. After all, Sam Walton wouldn't get involved in a venture of limited cash making capacity. And we all know that Sam was an honorable man, and that he wouldn't be trying to pull the wool over our collective eyes.
As to Earths water leaving the planet, I would say yes, it does, but only in very small amounts.There are water molecules present in the air all around us. The average velocity of any given molecule of air is ~330 metres/sec, the speed of sound. However, this is only the average. The velocities follow a standard distribution or Bell curve. Therefore an incredibly small number of molecules will attain escape velocity, and some of these molecules will be water molecules. If the altitude is high enough, the water molecule will be able to escape from the Earths gravity well entirely. This is why the moon cannot sustain an atmosphere - a small (but larger than Earths) proportion of the moons atmosphere would escape, and after a few million years it would be left with nothing.
The only other mechanism I can think of is through meteorite impact. Fragments of rock which contain embedded water could be hurled into space from such an impact. I doubt that water or Ice could do it by itself, due to boiling and mixing with the rest of the atmosphere.
Overall, then, bugger all water gets off Earth (or Mars), but a small teeny tiny bit does.
The water Mars once had is, for the most part, underneath the surface, much like permafrost. Frozen ice isn't much different from rock in a sense, it just gets churned up with all the other solids. However, because it is less dense, it does tend to stay towards the surface.
KTB:Lover, Poet, Artiste, Aesthete, Programmer.
There is no
Mars has no magnetic field, therefore no protection in the atmosphere from solar radiation that will take a water vapor molecule, make that molecule it's bitch, and split it wide open into oxygen and hydrogen, the hydrogen floats into space, and the oxygen combines with iron in the soil to make iron oxide, giving the planet it's rich amber hue.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
I am simply asking for a logical explanation of where the water went.
:-)
Duh, A giant Spaceship that turned into a giant vaccum cleaner (IIRC, Lord Dark-helmet lead the mission) and sucked up all of the oxygen (for their Perri-Air plants), and all of the water accidentally went with it.
They weren't as successful on their next mission:
Druidia
Doh!
Can anyone explain this? Am I missing something?
Many moons ago, the water on Mars held a closed session. All the hydrogen and oxygen got together to discuss the current state of affairs. Apparently, they had to spend a fortune in winter apparel and were pretty upset about the fact that the bikinis the Vogons sold them turned out to be wasted money. They decided that they were going to pack up and move to warmer climes.
Mars pleaded with them not to go, but they had made up their minds. Still, they felt somewhat sentimental, so they decided to leave behind a present. They did some molecular magic, and left behind a face, depicting the future Elvis (they can do this, becuase of a loophole in some Einsteinian formula dealing with temporal mechanics). Once this was completed, they hitched a ride, and spent the next few millions years on the sandy beaches of earth.
The rest is history.
Wrong.
The first article dealt with the origins of large channels on the surface of Mars. This deals with the presence of actual water presently on the planet.
Read before you flame the posters.
Of course it's dry, they never repealed Prohibition!
That's why on Earth we see so many Martian ships, they come here for the booze!
Linux O Muerte!
I know that planets are not closed systems. I know that debris often interferes with a planet's atmosphere. But I can't figure out how an ocean's worth of water could leave a planet. It wouldn't evaporate away; it wasn't sucked up and carried away. What explanation is there for a planet drying up? Could a giant asteroid slam into a planet and shake all the water off and into space? It doesn't seem likely that it would be bone-dry after that happened. What about the water vapour that went into the atmosphere? Can that be shaken off too? I'm not arguing that there is still water (or ice) on Mars, I am simply asking for a logical explanation of where the water went.
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Oh shit! I forgot to click "Post Anonymously"...
There is no reason to think it, considering Mars is relatively Earth-like and life happens very easily.
Life has not happened easily anywhere but Earth that we know of. Unless you have proof of life that has originated somewhere other than Earth, you can't make this statement. We have no reason to think that life occurs because of water, it just happened to be like that on our speck of dust. That is not to say I agree with the person who you replied to, because it very well is possible that there is life, but I won't believe it until there is proof.
: There never were lifeforms on Mars
This is very, very unlikely. Where there is liquid water, there is usually life. Life is made up of the most common elements in the universe, and for life to exist all you really need is water and some basic primordial soup. The chances of Mars never having had even the lowest form of bacteria are incredibly slim.
Again, you are taking science that you learned from watching Star Trek and applying it to real life. We have not found any life outside of Earth at this point in time. We may never find any, as the universe is really big, and, well, we aren't. So, the way a real scientist looks at the situation would be that, yes, it is possible for life to exist outside of Earth. We can not make any assumptions about that life, because we have a very limited amount of data to compare it against. When people base their knowledge on huge assumptions and make giant leaps of logic to support their beliefs, it invalidates the real science. You have to be skeptical, but open to new ideas. Try to understand, that by debunking someone's opinion with your opinion, rather than facts, you can't win. I know that there is no way humans can know anything 100% for certain, but, at least have some proof to back things up before you go around spreading your ideas to be facts. This is addressed to both people above me in this thread. Don't make science into a religion. There is a place for religion in people's lives, and there is a seperate place for science. When you base your "beliefs" on what you want to be true, rather than facts, that is a religion. I am not saying there is not any deities either. There may be, but I have no proof so I can't say.
So I won't be completely off-topic in this thread, let me just say that the only real way to know what's over on Mars is to send some people there. C'mon Nasa...it'd be fun! :o)
Mas vale cholo, que mal acompañado.
Frozen CO2, that is. What do you think the Martian ice caps are made of? (Well, mostly made of, anyway; there may be water ice at the poles too).
I don't know if it's water but it sure looks like flowing liquid to me.
Also, Here's a close-up
(MOC frame SP233806)
Does Guinness know about this?
Looks around nervously...am I allowed to say that? Please don't sue me!
--meredith
--meredith
Sometimes a scream is better than a thesis