Evidence For Liquid Water On a Frozen Early Mars

Matt_dk writes "NASA scientists modeled freezing conditions on Mars to test whether liquid water could have been present to form the surface features of the Martian landscape. Evidence suggests flowing water formed the rivers and gullies on the Mars surface, even though surface temperatures were below freezing. Dissolved minerals in liquid water may be the reason."

Comments

Re:Whatever happened to...

[Yvanhoe]

Still valid, but this is not the question. They are trying to determine wether big bodies of water existed on Mars. About Mars having huge quantities of water ice, we know it from several years, we even have pictures of it and even a map of Mars' aquifers.

Warmer?

[mc1138]

Is it possible that mars was warmer at a time? Either with a high level of CO2 or some other greenhouse gas that would have warmed the surface enough for running water? Maybe a little more dramatic but maybe even a slightly closer orbit?

Re:Warmer?

[drinkypoo]

If Mars had a significant amount of water it almost certainly also had an atmosphere, which retained heat.

Re:Warmer?

[scorp1us]

The atmospheric composition of Mars is predominantly CO2 (95%). If you take some eco-nut stance, the warming is linear, if you take a better-modeled stance you'll find it is less than that. (Diminishes logarithmically)

The real question is one of geology. Was Mars' inner core capable of producing a protective magnetic should like the Earth's? Remember Mars is smaller and will therefore cool faster. Our core, as the theory goes is made by counter-rotating spheres of liquid iron. With this, comes a thick, rich and creamy atmosphere shielded from the solar wind by the magnetic field.

The other question is what was the older composition of the thick atmosphere. Mars has too much methane, allegedly. Both methane and water vapor are far better greenhouse gasses than CO2. (Terrestrially we worry about CO2, because it is our biggest byproduct of human activity, and is stable molecule that either needs a plant to make it into sugar, or the ocean to sink it to the bottom).

The surface of Mars can reach 25C from being heated by the Sun. So there is a decent amount of energy.

OPINION: There is enough evidence to suggest that Mars could have been roughly equivalent to tropical - humid and warm. Weather or not its breathable is a whole other story with all that supposed methane...

Re:Warmer?

[mc1138]

That's a good point about the core of the planet, I remember reading that only the Earth has the protective magnetic field. Is it possible, and this will draw on my real lack of geology, but would a shift in orbit, say a collision that formed the "moons" of Mars pushed it out, and had enough either change in temperature of maybe a collision itself was disruptive enough to stop it from working?

Re:Warmer?

[smoker2]

The only problem I can see with all your comments is that you are assuming this took place a long time ago. We know that Mars can reach the mid 20s C and we also know that there are massive periodic dust storms.
Don't you think the storms would have eroded away the water gullies, or at least filled them with dust by now ? So I would say the formations are a lot more recent than "in the ancient past when Mars had a bigger atmosphere".

Re:Warmer?

[scorp1us]

That's a very good question. But the problem is one of sublimation. That is from solid state to gas. It happens in cold dry air. Snowcap-free Mt Kilimanjaro in Al Gore's "Incon. Truth" didn't melt from global warming. It sublimated because farming on the windward side made the air passing over the mountain drier.

The only way to keep the liquid water around is to have a denser, wetter atmosphere.

The problem with storms filling in gullies is that the dust particles are very fine, and have to be since there's not a lot of gas to move them. Without moisture, it is hard to bond to other particles (static charge being the leading cause) so its hard to have some drift that won't be blown away at the next dust storm.

That being said, there is evidence of water percolating. This won't be able to make large new gullies, but it will help maintain the ones that are there. And in fact, we have no idea of the gullies that exist that are filled in by dust. I can only conclude that the gullies we see are stable features left over from a time long ago. The "last of the line" so to say.

Re:Warmer?

[Geoffrey.landis]

...we also know that there are massive periodic dust storms. Don't you think the storms would have eroded away the water gullies, or at least filled them with dust by now ? So I would say the formations are a lot more recent than "in the ancient past when Mars had a bigger atmosphere".

The cross-section weighted average particle size of the dust particles is about 5 microns. Think of the particles as being ten times finer than the particles that make up talcum powder. It's more like cigarette smoke than it's like sand; it's not very abrasive, and doesn't do much in the way of erosion.

Sandstorms, like we have on Earth, do much more erosion.

However, yes, burial and deflation of features is a well-known effect on Mars. In some places the ancient surface is exposed, but in other places it is well buried. There are a lot of places on Mars where all you can see is the overlayer of dusty soil.

the next frontier

[IlluminatedOne]

We've so many things to learn from our red neighbor. I hate to put my tin foil hat on this early in the day, but I oft wonder how much data has been retrieved/analyzed/hypothesized upon that we (mouth breathers at-large) have not been made aware of. There are some tantalizing possibilities with Mars, both to learn of our past and to help forge our future. Like Buzz Aldrin, I think whomever the first Mars pioneers wind up being, they should not plan on returning...

Without giving the scientific method a nod, it easy to say 'of course there's water on Mars...duh!', but I still await the slam dunk chemical analysis. Too many things fool the eye from a distance, like so many men/women from across the room...

Coulda, woulda, shoulda

[elrous0]

Wow, another speculative article from someone one what COULD have been. I wish one of these days NASA would give me more than models, simulations, possibilities, and probes that are SUPPOSED to reveal actual conclusive evidence but which never do.

Re:Whatever happened to...

[b0ttle]

Researchers did an experiment simulating the temperature and pressure conditions on Mars, and found that liquid water is possible because of the perchlorates Phoenix found on the soil.
http://www.universetoday.com/2009/05/26/more-researchers-say-liquid-water-present-on-mars-now/

Re:Briny rivers

[Geoffrey.landis]

But if there was salt in the water, there was probably also life in that water. Life living in the salty water making it saltier by pissing in it every single day.

The thinking that brines may keep the water on Mars from freezing is not a new conclusion-- here ( http://www.liebertonline.com/doi/abs/10.1089/153110701753198927?cookieSet=1&journalCode=ast ) is a discussion of the concept from a few years back.

And, of course, the fact that the Opportunity rover found the Meridiani Planum site to be covered with evaporite deposits (mostly sulfate salts) contributes a lot...

Early Mars was warmer [Re:Warmer?]

[Geoffrey.landis]

Is it possible that mars was warmer at a time? Either with a high level of CO2 or some other greenhouse gas that would have warmed the surface enough for running water?

Yes, that's a good summary of the current scientific thinking. The Viking orbital images show a lot of the surface is sculpted by water-carved features, and the belief is that Mars originally has a much thicker carbon dioxide atmosphere, which provided a significant amount of greenhouse warming (*). With the loss of Mars' magnetic field, this thick atmosphere was slowly eroded away by the solar wind to the very thin atmosphere we see today.

Maybe a little more dramatic but maybe even a slightly closer orbit?

No, that's quite unlikely. Planets are hard to move.

-----
*Footnote: The media likes to pretend that there is some controversy about the fact that carbon dioxide produces greenhouse effect warming (because controversy sells newspapers), but in the science community studying planetary atmosphere, there is no controversy whatsoever. It is just physics.

If you search hard enough, you can find somebody who disagrees, and quote them, and say, "look, not all scientists agree!" And since this is /. I'm sure somebody's about to do that: the miracle of the internet is that these fringe thinkers have just as loud a voice as people who have actually stufied the subject. But nevertheless, the greenhouse effect is just physics. And relatively simple physics.

Re:Early Mars was warmer [Re:Warmer?]

[Geoffrey.landis]

My frost-bit annuals, planted well after the last-frost date for this location, beg to differ...

Yeah, this is exactly the kind of irrelevent arguments you tend to hear. To be fair, the idiotic media hype makes it seem as if this really is the argument for global warming: one warmer-than-average summer, and the headlines read "Global warming is here," and one worse-than-average hurricane season and headlines say "Global warming! Hurricanes are getting worse!"

Global warming is a long-term average rise of temperature over time scales of decades. One warm winter, even a handful of warm winters, has nothing to do with it. Temperatures still fluctuate-- climate change doesn't negate the existence of changes in the weather. And we're talking about the average heat balance of the globe-- any particular spot may still be warmer, or cooler, or unchanged.

The rule for northeast Ohio is, don't plant your tomatoes until the end of May. I planted mine at the end of April. Guess what? They're doing fine. Has global warming moved the growing season up by a month? No, you can't conclude that-- one season, one place, that's not relevant. Global warming is about averages, and about time scales of decades. Got that? Averages. Decades.

There is plenty of controversy, except among those taking funds from govt's, companies, etc who have a vested interest in global warming.

Yes, that's an amazing argument that just can't be refuted: just say that all the science that disagrees with your opinion is biased. You don't need to prove it, you can just assert it, and repeat it over and over until people get tired of arguing. It's such a great argument that you can use it to disprove anything, refute any amount of evidence, no matter how much there is. Evolution? The science establishment has a vested interest in saying it's established science! Did we really land on the moon? The science establishment vested interest in saying we did! UFOs in Roswell? The science establishment has a vested interest in pretending that they invented all that technology we stole from crashed saucers! Tesla invented free power and the oil companies had him killed? The science establishment has a vested interest!

Throw out all those studies, and we can talk.

Yep, that's the argument of the AWG deniers, all right. Throw out all the science. Exactly.

Re:Whatever happened to...

[TapeCutter]

It's been suggested recently that the perchlorates invalidated the micro-oven experiments, Apparently when heated they release large amounts of oxygen that would incerate any organics. Since I only have a vauge idea of what a perchlorate is, I have no idea if that's a valid criticisim. But given the possibility of ground water I think the methane hots spots are worth a closer look.

can we start terraforming yet?

[BigHungryJoe]

I'm not going to see any Mars terraforming efforts in my lifetime, am I?

That sucks. Why are we so slow?