Mars Had Surface Water for Eons

LukePieStalker writes "Far from being a one-time event, it now appears that surface water flowed on Mars for eons. Nasa has announced that, after descending down further into the Endurance crater, the Opportunity rover has found a 'razorback'. It is believed that this was formed by 'fracture fill' from the minerals in percolating water. Since this feature extends through several geologic layers, it argues for a long period of wetness near the surface. This would seem to substantially increase the chance that life once existed on the red planet."

Comments

How long is an eon?

[strictnein]

Is there an official length of time for an eon? I know it just means "An indefinitely long period of time" but when it comes to life developing the amount of time available is quite important.

... Eon is a very long period of time. Geologists refer to a Phanerozoic Eon which is about 550 million years long
The Archaeon Eon lasted over 2.1 billion years.

or is it:

An eon is the period of time it takes for a universe to come into being and then disintegrate again.

Re:How long is an eon?

[iamdrscience]

From Merriam Webster

1 : an immeasurably or indefinitely long period of time : AGE
2 a usually eon : a very large division of geologic time usually longer than an era b : a unit of geologic time equal to one billion years

So it looks like it's officially 1,000,000,000 years, but also a term for a really huge block of time.

Re:How long is an eon?

[Rei]

The problem is that the rovers are not equipped to be able to tell how old these rocks are - nor is it likely that any rovers any time soon will be able to do this sort of work. Labs that do radioisotope separation don't easily fit all of the categories ("small", "lightweight", "robust", and "self sufficient"), needed to send things to other planets. A sample return is a much more likely course before we can start dating these rocks.

Now, we can tell *relative* dates fairly easily with these rovers, but absolute dates are going to be a problem just using the rovers. There are some cases where you don't need radioisotopic dating, but I doubt they'll prove very useful here.

Re:How long is an eon?

[JustDisGuy]

It's as long as Slashdotters will argue over how long an actual eon is, when the reporter that used the term just thought it sounded good...

Re:How long is an eon?

[Snap E Tom]

More than a minute and more than a millenium, according to Universe Man's watch.

Re:How long is an eon?

[Rei]

That's a common misconception promoted by creationists.

Only dating methods such as radiocarbon dating (which we couldn't even begin dreaming of doing on Mars yet without a lot more study) are calibrated, and even then, it's a pretty minimal calibration factor (which on Earth we determine through dendrochronology and sometimes ice cores).

Most radioisotope dating methods not only don't have calibration, but have built-in error checking, such as isochron and concordia-discordia methods.

Re:How long is an eon?

[Rei]

That would involve multiple lines of dendrochronology which conform with each other and with the conventional historical account to all be incorrect, but not only that, but all be incorrect by the same amount compared to different artifacts. Hardly a realistic proposition. It also would require a truly massive calibration factor. Lastly, it's only applicable to radiocarbon dating, which is hardly the only dating method used.

The only time when the calibration factors become large are concerning objects from the 1950s onwards; nuclear testing really screwed up atmospheric carbon ratios, and introduced a geographical component. However, it gave a new benefit: we can now better track rates of carbon movement on a global scale. Also, there are the cases when carbon dating is not supposed to be used (which Creationists often use, of course); for example, ocean-dwelling organisms (which ingest recycled conveyor carbon) and organisms that spent their lives within a few hundred feet of a volcanic vent (which get deep earth carbon in addition to atmospheric carbon). This is known as the "resevoir effect".

Re:How long is an eon?

[sdo1]

How long is an eon?

Ask Universe Man. He's got a watch with minute hand, millenium hand, and an eon hand.

-S

Re:How long is an eon?

[Ayaress]

It's also worth noting that radiocarbon dating would be useless on Mars for two reasons: 1. It only works for formerly living material (all Terrestrial keeps the objective isotope of carbon around in a very specific ratio), and we have no confirmed fossils from Mars, and it would be a very long shot to count on finding them on a future mission. They'd be farther ahead just dating the rocks through other methods. 2. It's a relatively short-term dating (Creationists abuse this fact too, by pointing out that carbon dating on dinosaurs puts them right up to our geologic yesterday. The fact is, dinosaurs have been dead so long that all the carbon 14 in their remais is long since decayed beyond detectability). I forget the exact range, but as I remember, even going back as far as the KT boundry, it's already useless. If there was/is life on Mars, odds are most if not all of it has been dead for a very long time, and would again fall into the realm of more long-term dating methods. It would be more likely to produce good data if the probe relied on a dating method that could give results over a good chunk of the age of the solar system. On the off chance that we find something new enough to be interesting, I'd call that justification for a follow-up.

Mars

[Luigi30]

So does this mean that we might be able to find traces of water and/or life if we keep digging, or that the water is all gone?

Re:Mars

[Jim Starx]

If there was life then the right kinds of test should be able to find traces of it. I wonder if they've got the right stuff for the tests on the rover. There's only so much you can fit on that thing.

Re:Mars

[Rei]

We know there's still water there; unfortunately, it's in the form of ice.

As for fossils or traces of life... who knows? All we can say is that Spirit and Opportunity aren't going to be finding it unless it's macroscopic. They can only dig centimeters deep, and don't have the sort of magnification needed to see microscopic organisms.

Re:Mars

[cephyn]

Well there's multiple scenarios. First, there's the estimated amount of water that would cause the global areological features. Take that number, and subtract the estimated amount of water locked in ice at the poles -- we can estimate this through satellites. The North Pole is mostly water ice, South is mostly dry ice.

Now, that leaves a Heckofalot of water. (A Heckofalot is an official measurement, look it up. It's just short of a Hellofalot) Anyway, that water could be underground...perhaps in shallow aquifers, perhaps quite deep. It's hard to say, we just don't have the tools yet. Then there's the portion that would have been lost. Martian gravity is lower than Earth's, so it couldn't hold as thick an atmosphere as we do. So some water might have just evaporated off the entire planet. Also the Martian magnetic field is quite weak -- perhaps it was stronger before (there is some evidence for that) but when it weakened, it would have allowed solar wind and radiation to rip away the atmosphere and carry water vapor with it.

In short (ha) If we keep digging, we may find none, a little, some or a lot of water.

Re:Mars

[PornMaster]

First, there's the estimated amount of water that would cause the global areological features

Areological? Mars has areolae? I thought that was Venus.

-PM

Re:Mars

[Rei]

They already did that on Viking. The results were inconclusive, but suggestive of abiotic processes. The tests were as follows:

GEX (Gas EXchange experiment): Looked at gas level changes in martian soil vs. a control which it sterilized first.

LR (Labeled Release experiment): Looked for uptake of a radioactive liquid by gas presence, again vs. a control which it sterilized first

PR (Pyrolytic Release experiment): Like the LR, but in reverse; cooked the samples afterwards to see if they uptook radioactively tagged CO2.

GCMR (Gas Chromatograph - Mass spectRometer experiment): Heated soil samples and did a spectral analysis of them.

First, GCMR's results: Found an unexpected amount of ice, but found surprisingly *little* organics, leading scientists to conclude that some process was *destroying* organics on Mars.

For the others, the following would have been expected from each if there was life:

GEX, sample: O2 or CO2 released
GEX, control: No release
LR, sample: Labelled gas emitted
LR, control: No release
PR, sample: Carbon detected
PR, control: None

If there was no life, both samples and controls were expected to be the same. The real results?

GEX, sample: O2 released
GEX, control: O2 released
LR, sample: Labelled gas emitted
LR, control: No release
PR, sample: Carbon detected
PR, control: Carbon detected

In short, it was confusing, but was believed to be related to abiotic processes.

Fantastic!

[Limburgher]

Now we just need to evidence of other university mascots, and we can build a case for a Mars Bowl.

Water common?

[lecithin]

If we can confirm that there is/was water on Mars, what does this say about the rest of the Universe? Is water all that common? If we then associate water with the chance of life, out of the billions of stars, we just ain't alone. Insert Overlord comments below.

Re:Water common?

[LeahofRivendell]

Is water all that common?

Not only is water uncommon, the liquid phase is uncommon. Also, the reason it's so important is because it is less dense in the solid phase than the liquid phase, which allows it to freeze on top instead of on bottom, which in turn allows organisms to sustain life even when the body of water begins to freeze.

Re:Water common?

[AKAImBatman]

Water should be pretty common near stars as Hydrogen is the fuel which runs them. When combined with oxygen pulled near the star by gravitation, you find yourself with water. The difficulty is in finding it in liquid form. Planets and planetoids near a star will have their water blown or boiled away. This water will then travel toward the outer system. If no large body exists in the star's "temperate zone", then the water will continue on. If it hits a body outside of the "temperate zone", it will remain as ice.

At least, that's how I understand it.

Re:Water common?

[Ra5pu7in]

I had that same sort of thought. Confirmation that flowing water existed on Mars, even if none remains today, coupled with the number of asteroids / comets that have ice does tend to imply water is reasonably common in our universe. Two planets within a certain size range and within a certain distance of their star both having had water seems a better argument for the existence of water on other planets around other stars. (No Overlord comment - it would just confuse the puny humans I am controlling.)

Re:Water common?

[pclminion]

Is water all that common?

Probably yes. Hydrogen and oxygen are among the most abundant elements in the universe.

The unusual thing about Earth is that the environment is at the triple point of water. Water is able to exist as a gas, liquid, and solid all together in the same environment. This is only possible in a narrow range of temperatures and pressures. So water is probably very common. Liquid water, OTOH, is not.

As for why water is important for life, see one of my older comments.

Re:Water common?

[Artifakt]

To expand on Leah's comment - There are other liquids that are very simple atomically so they exist a lot around the universe. Two of these are Methane and Ammonia, both liquid under some circumstances. Because they are not polar molecules, the range they stay liquid is much narrower than for H2O. Their ice form is denser than the liquid, so lakes or oaceans of them will freeze from the bottom up, and there won't be an insulating layer to keep them from freezing over completely. So not only life as we know it, but some of the alternatives that we guess just might be possible are affected. Ammonia based life would only be possible in environments with a colder AND much narrower temperature range than Earth's. Freezing winters would be a critical problem instead of something life might be able to adapt around.

Re:Water common?

[Rei]

"Not only is water uncommon, the liquid phase is uncommon"

That should have read:

"Water is not uncommon; only the liquid phase is."

Our solar system is jam packed full of ice. Heck, Uranus and Neptune are best described as "Ice Giants" instead of "Gas Giants", due to their expected ice cores. Ice dominates the moons in the saturnian system, the kupier belt and oort clouds are composed mostly of ice, etc, etc. In fact, it is even theorized that Earth got its water from comets.

Re:Water common?

[Rei]

Erm, minor correction: Uranus and Neptune have ice mantles, not cores. Their cores are expected to be rock. Their atmospheres are relatively thin compared to the true "Gas Giants".

Re:Water common?

[Rei]

This requires a couple of assumptions:

1. Life can't exist in high-pressure environments.

Higher pressure environments have much wider ranges for the liquid phase of ammonia and methane.

2. Life cannot develop on planets with freeze/thaw cycles.

I see no reason why this should be the case. In fact, with methane and ammonia, you don't have to worry about cells being ruptured by freezing, so long as they don't have stiff cell walls.

Further, a "cell" is not the first life; you first have molecules that tend to catalyze the production of "similar", if not exact, molecules. The processess regionally take off. Groups of molecules that more accurately catalyze the production of their member molecules form "hypercycles" - regions which, while not distinct from each other, catalyze their own development. As these hypercycles begin to become distinct and compete with each other, they end up being walled off into "Ur-cells/Protocells" (depending on your terminology).

At least, that's one theory I've seen presented, which seems reasonable.

3. It is not hotter near the bottom.

There is no particular reason to expect this. In fact, in many environments in the universe where we expect there to be liquid, this is exactly what we expect; geothermal heating, tidal heating, precipitative convection heating, etc.

4. There are no dissolved molecules that can act as "antifreeze"

Pure solutions of methane or ammonia are unlikely.

5. Life requires a liquid solvent to develop.

While this is probably true, we don't know this for sure yet.

Re:Water common?

[markmier]

Ummmm... ammonia is quite polar. NH3 dipole moment is 1.5 D. Water is 1.8 D. (methane is indeed nonpolar).

At 1 atm pressure, ammonia melts at -108F, and boils at -28F (from GPSA handbook). So it has an 80F range of liquidity, whereas water has 212F. However, like you said, ammonia solid is more dense than the liquid. Water is one of only a very few materials (gallium is another, I can't remember any others but I bet there are some) that are more dense as a liquid.

By comparison, methane melts at -296F and boils at -259F.

Just your friendly neighborhood chemical engineer! :)

Re:Water common?

[Rei]

I'll second this. I once was debating with someone over whether silicon-based life was possible, and as I researched, I was actually surprised by the chemical complexity available in silicon compounds. Silanols, for example, are found all over in Earth's oceans, and can form sheets, catalyze reactions, and all sorts of other things. While your basic "silicone" is pretty simple (chains of Si-O-Si-O... etc), so is your basic N-ane hydrocarbon chain. What makes organic chemistry interesting is functional groups, and silicone backbones can handle them just as well as carbon backbones can. Then there's silicates (Si-O tetrahedral structure), which have all sorts of interesting properties that have made them valuable in industry (for example, zeolites - in which some of the Si's have been replaced by other metal atoms - act like molecular sieves, and can have "superacid" properties).

Re:Water common?

[gamgee5273]

Carl Sagan, in Cosmos, believed that, when (and yes, he was a firm believer of when) we encounter life on another planet we should not be surprised if we find silicon-based life.

Popular imagination doesn't think of alien lifeforms as anything other than carbon-based (see almost any popular SF TV show in the past 40 years) or cyborgs (the Borg in Star Trek, of course). The best example of a silicon-based lifeform in popular fiction is the xenomorph (the aliens) from the Alien and, frankly, the fictional biology/biochemistry of the xenomorph is close to what you are describing.

I just hope we run into things that are a little less agressive than xenomorphs. :)

Re:Water common?

[Pharmboy]

Why water? Many Sci Fi authors have predicted life cycles based on other substances, in various and other temperature gradients.

I think the main point here is that we know that life can grow where there is water, and we have some pretty good ideas what to look for. For instance, we are looking for proof of water on Mars, and then we know to look where the water USED to be in order to find where life MAY have been.

When it comes to life that isn't carbon based and/or came from water, we simply don't know what to look for. We could be looking right at it and not see it because we have no point of reference, no experience, no tell tale signs that say "life was/is here". That doesn't mean life doesn't exist without water (or without being carbon based). It just means we would be unlikely to understand what we found with the limited tools on a probe unless the think came up and started waving "hi" to us.

Considering that water is relatively common in the areas of the solar system that we would THINK there could be life (venus thru mars + moons of outer planets), the smartest investment we can make is to look for the kind of life we know can exist, where we think it can exist. This means where liquid water is or was.

Re:Water common?

[Artifakt]

NH3 Polar, well, yes, as you point out, but if you don't mind me qualifying it a bit, I'd say NH3 isn't usefully polar, in that it doesn't have the equivalent of Van der Walls forces between liquid molecules at a strength sufficient to much help stretch the range of liquidity (a tiny bit, but not much). The 2 Hydrogens in a water molecule don't line up on the opposite sides with the oxygen atom in the middle, but form a rather pronounced bend. By contrast the three hydrogens in Ammonia don't leave the Nitrogen sticking out by itself. They may not maintain perfect 120 degree angles in a flat plane around the N's "equator" under all conditions, but they are pretty close to it.
When you analyze this geometrically, we're talking about an inverse square law force (electromagnetism), and various sine or cosine based equations for the resulting angles in determining the resultant forces. Then you have some fairly small adjustments to factor in the different masses and orbital diameters of O and N, and so on.
What this all ends up meaning is the resulting 80 degrees F will be a bit broader than Methane's totally non polar 37 degrees F, but it's still less than half the 180 degrees F for liquid water, and not nearly 1.5/1.8 of it. (I assume your 212 F is a typo - you obviously know this stuff better than that).
It's really the more limited question of how NH3 molecules react solely with each other when we're talking about the freezing of an entire ocean of the stuff, not how NH3 and H2O (or some other interesting combinations) interact (many of which can be quite polar crystalization reactions).
Now as regards life forms, what applies to a relatively pure liquid is more than usually not something we can extrapolate too much to a mixture, so I wouldn't read too much into it. Our one example of liquid oceans is not exactly pure H2O, after all, and showing that there are some reasons life is less likely in close to pure Methane or Ammonia doesn't limit a lot of other possibilities.

Re:Water common?

[Xilman]

NH3 Polar, well, yes, as you point out, but if you don't mind me qualifying it a bit, I'd say NH3 isn't usefully polar, in that it doesn't have the equivalent of Van der Walls forces between liquid molecules at a strength sufficient to much help stretch the range of liquidity (a tiny bit, but not much).

By a hell of a lot, actually. Compare its liquid range with methane, which has essentially the same molecular weight (CH4 = 16, NH3=17, H2O=18).

NH3 is also usefully polar in that it allows a good many salts, acids and bases to disolve in it, again like H2O. Methane doesn't.

The 2 Hydrogens in a water molecule don't line up on the opposite sides with the oxygen atom in the middle, but form a rather pronounced bend.

Correct.

By contrast the three hydrogens in Ammonia don't leave the Nitrogen sticking out by itself. They may not maintain perfect 120 degree angles in a flat plane around the N's "equator" under all conditions, but they are pretty close to it.

Incorrect. The NH3 molecule is substantially pyramidal. The H-N-H angle is close to 107 degreesIt's the flipping between the pyramidal configurations that's the basis for the ammonia maser. (Actually, it isn't, really, but unless you want a digression into molecular quantum mechanics that explanation is good enough and will have to do.)

Now as regards life forms, what applies to a relatively pure liquid is more than usually not something we can extrapolate too much to a mixture, so I wouldn't read too much into it. Our one example of liquid oceans is not exactly pure H2O, after all, and showing that there are some reasons life is less likely in close to pure Methane or Ammonia doesn't limit a lot of other possibilities.

Good! It is extremely unlikely that an ocean would be pure ammonia, any more than our oceans are pure water. It's rather likely, I suggest, that a predominantly ammonia ocean would contain a large amount of disolved water, which would raise the liquid range and make the chemistry both different and probably more interesting from a biochemical point of view.

Paul

Re:Water common?

[juan2074]

5. Life requires a liquid solvent to develop.

While this is probably true, we don't know this for sure yet.

Good point. So many 'scientists' claim that water is a requirement for life, but that may not be true. Any other liquid solvent may not be necessary. If an organism can get its energy and dispose of waste products without a solvent, it is not a requirement.

You are right. We just don't know this for sure.

Why is it surprising?

[Neil Blender]

If Mars had water, why would it not have it for a long time?

Re:Why is it surprising?

[xenophrak]

I think the common dogma is that a catastrophic event happened some billion years ago where Mars lost its magnetic field. The loss caused the upper atmosphere to be evaporated from solar radiation that was then allowed to pass into the lower levels.

One might surmise that since the Earth has a molten fluid core and routinely undergoes magnetic reversal that Mars once had the same type of core, but it may have cooled and solidified, rendering the field inoperable.

Whatever it's worth, I think that the ammonia presence is far more interesting than the traces of water.

Re:Why is it surprising?

[Cecil]

A significant amount of ammonia in the atmosphere that has not been broken down by solar radiation would signify that it is being generated on the planet currently. The only two methods we know of that would produce enough ammonia to be detected are active vulcanism, specifically an active volcano somewhere, which we have never seen, or microbial life. I suspect the original poster is more excited about the latter possibility.

On 20th July too.

[Skiron]

Shame them didn't actually find water today of all days - 20:17:43 20 July 69

Chances of Life

[Dominatus]

I don't quite see the obession with finding life on Mars.

In terms of science, we know it's possible, it's not an issue of "can" it happen it's an issue of "where" did it happen again. We also know that if there was life it's doubtful it went beyond the microscopic range as not only is there no evidence of that, but life existed on this planet for eons w/o going past the microscopic range. It's arguable that the natural result of life is not always complexity and size.

It seems to me the only reason people are obessed with finding life on Mars, or anywhere else for that matter, is to fill some urge that if they do, to less scientific minded (read: religious) people will be proven wrong.

Re:Chances of Life

[QEDog]

I don't quite see the obession with finding life on Mars.Because by finding life somewhere else we can learn a lot about life on earth.

What is life? Really? You will find many people with slightly different definitions just on life on Earth.

What about other planets? What if life in mars, the DNA strand twists the other way? Or what if there is no DNA. If the DNA is the same, then, maybe life in Mars and Earth have a common origin. If not, what common things do we see? What is the minimum requirement for life? And these are just a few questions I can speculate on. I think we can lear about ourselves, and the fundamentals of life on Earth by finding life somewhere else.

And that is all without any religious (or anti-religious) agenda.

Re:Chances of Life

[Jim Starx]

Because all those musings about we know this was probable and that is likely and blah blah will remain theoretical until evidence is found in support of them. That's the natural progression of science.

Re:Chances of Life

[devilsadvoc8]

How do we "know" that it didn't go beyond the microscopic level? Take a rainforest, insert cataclysmic event or two (or even drastic climate change), wait a few million years- now tell me what signs would be visible from the surface of the rainforest? I would gather that there would be not one sign whatsoever from the surface let alone from satelitte imagery.

I think that the interest lies in the possibilities- if this solar system had two (minimum) planets with life then #1 earth is not such a freak accident and #2 there are millions upon millions of life bearing planets out there and intelligence must exist external to earth.

Re:Chances of Life

[mr_pins]

I don't think so. Even if I grant that "we know it can happen", the bigger question is "How likely is it to happen?"

Finding evidence of life on Mars would be extremely helpful/interesting in begining to answer this question. I'd say that is the main reason people are so "obsessed" with finding life on Mars.

Re:Chances of Life

[lukewarmfusion]

I know scientists that believe such a discovery would discredit religious beliefs... but many religious folks I know have absolutely no problem with life on other planets (or some a source other than that described in the Creation story).

One friend of mine, a pastor at a non-denomination church, argues that the Creation story is not a literal history; science can never remove God completely, no matter the discoveries.

Really, the obsession with life on Mars (or other places) has a lot of sources. As we learn more about the Universe, human beings don't want to be alone in it. We want to try and answer questions that may not have answers here on Earth, including the origins of life and the nature of evolution. Wouldn't you like to be there to witness the natural beginning or end of life on an entire planet?

Re:Chances of Life

[Sloppy]

In terms of science, we know it's possible, it's not an issue of "can" it happen it's an issue of "where" did it happen again.

But if you find it, you also get to ask how it works. Imagine what finding life, especially if it turned out to be unrelated to Earth life, would do for biochemistry. Life implemented without the usual DNA/RNA, or implemented with different encodings or whatever, would be pretty neat to study. Probably all sorts of applications, too.

It seems to me the only reason people are obessed with finding life on Mars, or anywhere else for that matter, is to fill some urge that if they do, to less scientific minded (read: religious) people will be proven wrong.

No way, you're totally wrong. Science has value all on its own, whether the discoveries piss someone off or not. Do you think Galileo published his works just to annoy the church?

Re:Chances of Life

[namidim]

First, since when does the presence of life on other planets contradict the existence of a god? The earth isn't flat and the sun doesn't orbit us either, yet somehow world religions go on. Second, how is it so hard to see the innate value and magnitude if we were to discover life on mars? Finally, why is the discovery of life only interesting if it involves little green men. Microbial life on mars would be a watershed event in it's own right. I can't even begin to list all the medical, philisophical, biological, etc implications that would immediately result.

Re:Chances of Life

[DynaSoar]

"I don't quite see the obession with finding life on Mars."

I do. But then I'm a scientist. I want to know stuff. I want to know as much as possible, and have other people in other fields find out as much as possible, because you never know what good things that can improve the quality of life can come of it. And actually, that last part is justification so that society will continue funding my research. Mostly, I just want to know stuff. It's why I became a scientist.

Also: because that's what humans do. They explore. They want to know their environment. I could probably come up with a decent hypothesis regarding cognitive dissonance driving humans' desire to decrease the number of unknowns in their environment in order to maximize their comfort level and probability of survival. But then that's the other thing I do as a scientist. Come up with hypotheses. Fact is, for whatever reason, or maybe no reason other than evolutionarily determined hard wiring in the brain, it's what people do.

Anyone not interested is free to focus their attention elsewhere. And dollars to donuts they themselves will have something like this that drives them that other people may not understand.

I'm sure you're right, that some people would use such a discovery as proof for and/or against some religious viewpoint. Hell, they did it with rock and roll music, and pretty much anything you can think of that they can use as leverage against each other in their power games. Good for them. Everyone needs a hobby, it gives them purpose in life, and it keeps them out of my hair.

Re:Chances of Life

[KevinKnSC]

In terms of science, we know it's possible, it's not an issue of "can" it happen it's an issue of "where" did it happen again.

Part of the fascination is that we don't know if it's possible. We think that it might be, and the odds seem to be in favor of it, but we won't know for sure until we find some evidence of it. That's how science works.

It seems to me the only reason people are obessed with finding life on Mars, or anywhere else for that matter, is to fill some urge that if they do, to less scientific minded (read: religious) people will be proven wrong.

First, I think this is a false dichotomy, as if a God who created the Heavens and the Earth isn't capable of creating life in multiple places. See Out of the Silent Planet by C.S. Lewis.

Second, I've met a lot of scientists, and very few of them seem to be motivated by the desire to prove religious people wrong. Most of them (and all of the good ones) seem motivated by curiosity and a desire to understand the world and universe around us. That, coincidentally, is the same impulse behind most of the religious people I know, as well.

Re:Chances of Life

[Dominatus]

"Part of the fascination is that we don't know if it's possible. We think that it might be, and the odds seem to be in favor of it, but we won't know for sure until we find some evidence of it. That's how science works."

We do know it's possible, evidence is right in front of you. Earth. Earth isn't some magical existence according to science, it's just a planet. If it can occur then it will occur, and given enough time it must occur.

Re:Chances of Life

[Kphrak]

I've never understood the thinking that if life was found on another planet, all religious people's (they mean "Judeo-Christian and maybe Islamic", not "religious") heads would explode, and God Himself would vanish in a puff of logic. What's to stop God from creating life on another planet?

The idea that Earth was the center of the universe originated with some Greek philosophers (Aristotle and Ptolemy were among these), and the idea was actually quite controversial even then. The only reason why it became canonical (plenty of Christian scientists, including Johannes Kepler, argued against it) was that it was one of the few things left from the ruin of the ancient world by the time monastic scribes got hold of it, and the ancients were so impressive that it was hard to imagine anyone one-upping them at the time. Such a theory is never mentioned explicitly in the Bible, and it's pretty doubtful that any religious person would care about its collapse. Unless there are still Christians who believe that the orbit of any planet can be described by a perfect circle...

Re:Chances of Life

[jdavidb]

I'm a literal (6000-year) creationist, and I fail to see how the Creation rules out life on other planets. It just isn't in the original text, although I suppose a lot of people (both religious and non-religious) have tried to read it into it.

Re:Chances of Life

[b-baggins]

What? It's a problem with religion that science can't disprove the unprovable?

Physical science operates from the paradigm that there is no God (or that he is completely immaterial to the formation and operation of creation - a distinction without a difference). How then can it ever expect to explain God one way or the other, and how can religion be criticized for the failure of science in this regard?

Sheesh. People act like science is the ultimate finder of all truth. Science is simply a tool that tries to explain the observable world. Things which cannot be observed and measured can never be explained by science. That is not the problem with the thing that cannot be measured or explained, it is simply a limitation of the tool being used.

Re:Chances of Life

[b-baggins]

Yeah, and given enough time, a 747 full of encylcopedia salesmen name Bob will fly out of a black hole.

The key concept you're missing here is meaningful or statistically significant.

Re:Chances of Life

[Sgt York]

Mostly, I just want to know stuff. It's why I became a scientist.

Reminds me of a fortune I saw once. "As an adolescent I aspired to lasting fame, I craved factual certainty, and I thirsted for a meaningful vision of human life - so I became a scientist. This is like becoming an archbishop so you can meet girls."

It rings so true for a grad student in the doldrums of the 4th year.....

But I still just want to know. It's a curse. If my PI would let me pursue all the tangents I want to pursue, I'd be here for 15 years with no coherent project. He once told me that science is like a hydra; if you answer one question, two more pop up in it's place. The nad news is that you can never kill the hydra, but there is some good news. Being a scientist does not mean you have to kill the hydra. Being a scientist just means you have to fight it. The Zen of biochemistry. Heh.

Razorbacks...

[jlockard]

razorback

• n 1: thin-bodied mongrel hog of southeastern United States that is a wild or semi-wild descendant of improved breeds [syn: razorback hog, razorbacked hog]
• 2: any of several baleen whales of the family Balaenopteridae having longitudinal grooves on the throat and a small pointed dorsal fin [syn: rorqual]

Yep, I guess that would be proof of water.

Still waiting for fossilized remains.

[LeahofRivendell]

To me, that's the only concrete proof of life on Mars. Life is complex--there's more to it than water.

Eon = Division

[Valiss]

The longest division of geologic time, containing two or more eras. For example, an era where Mars had water and an era afterwards, where there was no water.

I never doubted there was water on mars..

[slungsolow]

simply because there are giant chunks of ice that have been visible on its surface for as long as I have been alive. Where there's smoke...

How about the following image?

[CyberGarp]

I scan the raw feeds from Mars regulary. I ran across the following image: Mars Photo. Now if that doesn't significantly improve the odds of life on Mars I don't know what does.

Another possibility

[techno-vampire]

If water is dripping into a gap caused by a fault, it might not take that long for dissolved minerals to fill the hole. Considering how big stalactites and stalagmites can get in a few thousand years with just a slow drip, how long would this take with periodic flooding followed by a long dry spell?

Re:Another possibility

[NTAC]

This is not why they think liquid water existed on the surface for a long time. It's because the 'razorback' cuts through rock that also shows evidence of water. That means that liquid water existed when the original rocks formed, and again much later when the 'razorback' formed.

Can't increase chances retroactively

[ColonelPanic]

This would seem to substantially increase the chance that life once existed on the red planet.

No. Life did or did not exist on Mars, but either way, its chances are over.

What these results might increase, if true, is the chance of our discovering evidence that life has existed on Mars.

Re:Can't increase chances retroactively

[fiannaFailMan]

Okay then. It "increases the chances that it is true that life once existed on Mars." Happy now?

Re:Can't increase chances retroactively

[ViolentGreen]

Is it seriously necessary to pick apart posts and respond on technicalities? I don't think there is really much doubt about how the comment was meant. The meaning came across fine.

This remindes me of those exercises that I did in grade school where I had to write specific instructions on how to make a peanut butter and jelly sandwich. The teacher would then make a mockery of the instructions by making a mess with the ingrediants.

Few people here are lawyers so few statements are going to be hole free. Most statements here and elsewhere in the world require a little common sense to interpret correctly.

Being excessively anal accomplishes nothing.

too bad Mars didn't have more mass

[frankie]

If only Mars had a deeper gravity well, it would still be wet today, and probably alive.

Of course, if it were, either we would have gone there and slaughtered the natives already, or vice versa.

Instead, Mars and Venus serve as object lessons on the narrow window of planetary viability.

article mirror

[Anonymous Coward]

Freecache of article image

Surface water on Mars existed across a significant span of time, not just for years but eons, suggest new findings made by NASA's Mars rover Opportunity.

Within a few weeks of its landing on Mars in January 2004, Opportunity revealed what was uppermost on the twin rovers' agenda: that bodies of liquid water once existed on the surface of Mars. But the evidence proved what could have been only a solitary event - a single wet episode.

The new discovery, reported by NASA's Jet Propulsion Laboratory on Friday, pushes the boundaries significantly further back, into geological timescales.

After motoring down several metres into a the large Endurance crater, Opportunity has found what science team member Jack Farmer of Arizona State University calls "razorback," a ridge of thin, jagged vertical plates sticking up at the edge of a flat expanse of bedrock.

The team suspects that the ridge is a layer of rock that formed when earlier layers of rock cracked, and mineral-laden water percolated through the cracks leaving deposits behind, forming veins, or "fracture fill". Those deposits formed rock harder than the surrounding material, so as the rock eroded away it left this harder ridge behind. The fractures, Farmer says, may have been caused by the impact that produced the crater.

Salt crystals

The surrounding rock is the very bedrock that Opportunity has been studying ever since its arrival on Mars, first in a tiny crater called Eagle, and for the last month in the much larger Endurance crater.

In both places, the layered bedrock has provided multiple lines of evidence - unusual minerals, voids left by dissolved salt crystals, and hematite spheres - showing that liquid water once flowed there. And at the Endurance site, this evidence for water extends through five successive geological layers, or units, extending back in time from the original layer.

But the new "razorback" find dramatically extends this record. Formation of such crack filling material requires liquid water, but at a time so much later that these different layers of marine sediment had time to be compacted into stone, hard enough to form sharp cracks rather than crumbling.

The actual time span has not been estimated, but it reveals enough time to strengthen the possibilities that life could have evolved on Mars. The team is expects to spend most of this week analysing the razorback with the rover's various spectrographs.

Dwindling sunlight

Meanwhile, there was great excitement on the other side of Mars. The rover Spirit, skirting the edge of a hill called West Spur on the edge of Columbia Hills and preparing to drive up it, has now driven over an outcrop of bedrock - something that had never been seen before at Spirit's site in Gusev crater.

"Eureka! We have found it!" exclaimed Matt Golombek of NASA-JPL, a science team member. "Spirit has an outcrop under the rover wheels. And an outcrop is the currency for geologists." Studying it should help reveal the geological history of the Gusev site.

Both rovers are in the most scientifically interesting and technically challenging terrain yet, though both are also somewhat limited by the dwindling sunlight and plummeting temperatures as midwinter approaches in September. And both remain healthy, despite one balky wheel on Spirit, having more than doubled their 90-day design lifetimes.

Not mass, magnetosphere

[kippy]

Both Mars and Venus are bone dry because they have little to no magnetosphere. This allows water vapor to be broken into H and O by UV radiation and since the H is light, it can acheive escape velocity much faster when hit by unhindered solar wind.

My guesses about water and life on Mars.

[MtViewGuy]

Personally, I think that once Mariner 9 showed what is very likely former riverbeds on Mars, it's obvious that in the distant past, Mars had water and very likely some form of lower-level lifeforms.

In my opinion, here's what happened on Mars:

1. In the distant past when there was flowing water on the plant, life did evolve, with the likely chance that we had fairly advanced plants lifeforms and lower level animal lifeforms.

2. Alas, when the atmosphere thinned, the surface water evaporated, essentially killing all lifeforms except for (at best) forms of bacteria and possibly algae that could survive in today's extremely severe Mars climate, living off the water trapped under the surface of the planet.

3. I think when the Mars Science Laboratory lander/rover reachers Mars in 2009, it will find that life does exist on the planet today in the form of bacteria or something related to it.

Re:Now if only we could find intelligent life...

[Anonymous Coward]

Yeah, but he also called you stupid. I think that's a fair tradeoff.

Mars may tilt sideways for more extreme climate

[peter303]

Earth has a large moon which stabilizes the tilt angle of its rotation axis. The Earth bulges at at equator from its rotation and the pull of the moon. The moon pulling on this bulge keeps the earth's axis steepening much more than it is now- a 23-degree tilt. The tilt angle creates the seasons. If it tilted more, there'd be warmer summers and colder winters.

Mars lacks a significant moon. Therefore people speculate that it could tilt all the way over on its side sometimes and have extreme seasons. Maybe even extreme enough to melt the carbon and water ices at the poles and permafrost.

Dynosaur skeletons and oil

[HermanZA]

That is all they need to find, to cause a new space race.

Existance of Life

[Harpua22]

"This would seem to substantially increase the chance that life once existed on the red planet" I think a more accurate statement would be that this increases the chances that we might find evidence of carbon based life forms having existed at some point on mars. It is theoretically possible for life to exist without water by using another liquid solvent as a substitute. One often proposed substitute is ammonia (see article http://www.daviddarling.info/encyclopedia/A/ammoni alife.html/ ). People seem to think narrowly about the possibilities of life, and often constrain their thought process to life that is, at a very basic level, similar to life on earth. Granted, since carbon is fairly prevalent throughout the universe there is certainly a good chance of it forming life in areas other than earth, but we should keep in mind that it is not (at least theoretically) the only option.

Re:Moderators, don't be asinine.

[Jupiter9]

It all started with ths:

Read me

I'm sure they're having intermittent problems that will eventually get worked out over the coming days.

Slashdot Categories and Mars...

[rulethirty]

Aren't there enough articles about Mars to warrant its own category within Slashdot?

NewScientist Scoop?

[captainClassLoader]

Well, this article is pretty fascinating, and not only for its content - None of the other space exploration sites I visit regularly seem to have this information - At most, they talk about Opportunity's discovery of the Razorback feature, but no discussion of analysis. Has NewScientist scooped everyone on this discovery, or was this publicized prematurely?

No tinfoil required, really, just an observation.

No one would have believed...

[Darth23]

...in the last years of the 19th century, that human affairs were being watched from the timeless worlds of space. Few men even considered the possibility of life on other planets. No one could have dreamed that we were being scrutinized as someone with a microscope studies creatures that swarm and multiply in a drop of water.

And yet, across the gulf of space, minds immeasurable superior to ours regarded this Earth with envious eyes, and slowly, and surely,

they drew their plans against us.

In other news

[DJStealth]

In other news, it has been found that previous Mars rovers that have dissappeared onto the martian atmosphere have been sent back eons in time due to a glitch in calculations of relativity. The failed rover landed in a creater and had a fuel leak, with the spilliage causing creavases in the land called 'razorbacks'.

Life IN Mars

[Randym]

This would seem to substantially increase the chance that life once existed on the red planet.

Every planet probably has microscopic, non-oxygen-using life INSIDE it. (In fact, it may even be NON-microscopic.) Just because we don't find it lying about the surface does not mean that it did not exist.

When we talk about 'life on earth' it's assumed that we are talking about life on the *surface* of Earth. But that surface is *7 miles thick* [depth of ocean] and the radius of Earth is *4000* miles. And we know non-oxygen-using extremophiles and Archaea exist *here*. Why not there?

Re:hmm

[drinkypoo]

Slashcode was recently "updated". Since there's no way to test slashcode without exposing to the users, which is to say you and I, this unfortunate fact was unavoidable.

Lately I've been having numerous page rendering errors, and I haven't changed my browser, so I'm basically assuming that they fucked up some part of slashcode and are casually working on repairing it.

Re:Where are the zealots lately?

[egomaniac]

Where do people get this stupid (more importantly: wrong!) idea that religion is incompatible with science?

Science has proven, beyond a reasonable doubt, a number of things that directly conflict with Biblical teachings. For instance, we know that the Earth is much older than the chronology in the Bible allows for. We know that man evolved from apelike ancestors. We know that Noah's flood did not occur.

And yet I know a number of people who will swear, based on no evidence whatsoever, that all of the world's scientists are wrong and the Bible tells the true story. In other words, they believe that nomadic herders who lived thousands of years ago knew the truth and that millions of modern scientists, the guys who invented computers and lasers and put men on the moon, have no idea what they are talking about.

It's possible, I must admit. Of course, it's also possible that there is an invisible unicorn standing right next to me. But I think that believing an old book over this incredible body of scientific knowledge, and worse yet trying to keep said scientific knowledge out of our classrooms in favor of religion, is both delusional and dangerous. Religion and science are very much enemies, unfortunately.

You may not personally have a problem with the idea of evolution or whatnot, but sadly there are a tremendous number of ignorant Christians who do, and they continue to oppose scientific advancement at every turn.

Is it possible that... (Hypothesis)

[lcllam]

...maybe Mars was an older form of the Earth, and as the sun cools and the heat is drawn inwards towards the center of the solar system, that maybe Venus is a young Earth?

What I've always found weird is that, based on the assumption that the planets were formed from the same 'cloud' of interstellar particles, how they've evolved with such different compositions. There's clearly activity that we don't know about going on.

Suppose during the birth of the sun, it was immensely hot, and began cooling as the fuel for fusion burned off. Initially, life formed on one of the outer planets, as temperature and perhaps a few said unexplained phenomena created the so-called 'life conditions', and that this gradually moves inward as the planets cool.

We don't really have a timeline on when this happened, but I'd expect it to be longer than you or I have ever lived. Maybe it's actually been long enough that all traces of civilization have been eradicated by natural forces (such as a meteor impact). We've only been fiddling with rocks on the surface on Mars, but closer to home, we only find traces of older civilizations when we unearth then from several meters below the surface.

Um.. no, I will have to say there's no supporting evidence.