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Mars pebbles prove water history
May 31, 2013 8:39 AM   Subscribe

Scientists now have definitive proof that many of the landscapes seen on Mars were indeed cut by flowing water.
posted by MisantropicPainforest (68 comments total) 20 users marked this as a favorite

 
Mars radiation fears won't deter Nasa: the will to explore will prevail
posted by Artw at 8:41 AM on May 31, 2013


Canals indeed. John carter wasn't just a space traveler he was a time traveler.. duh.

yeah.. I know
posted by edgeways at 8:47 AM on May 31, 2013 [1 favorite]


...again
posted by DU at 8:49 AM on May 31, 2013 [2 favorites]


I came to doubt, but that picture really is a slam dunk. The number of things that would have to happen to pull those elements together coincidentally is off the charts.
posted by Tell Me No Lies at 8:50 AM on May 31, 2013 [1 favorite]


Yes, but I might push back against using language as strong as "definitive proof" only because it implies 100% certainty. There is always some uncertainty. Do we know much about wind speeds on Mars 3 billion years ago? One person's rounded fragment is another person's angular fragment. Etc. Etc. I would love to read the reviews of the peer reviewed paper just to gain some insights about potential problems with the conclusion.

All that said, I am convinced!
posted by Seymour Zamboni at 8:52 AM on May 31, 2013 [2 favorites]


I came to doubt, but that picture really is a slam dunk. The number of things that would have to happen to pull those elements together coincidentally is off the charts.

Alternatively, the budget cuts at NASA have severely affected their ability to fake pictures.
posted by Tell Me No Lies at 8:52 AM on May 31, 2013 [3 favorites]


If you scroll down, you can also see that NASA has confirmed the existence of Nikon lens caps on Mars. That picture really screwed me up for a second.
posted by Rock Steady at 8:54 AM on May 31, 2013 [12 favorites]


I don't see any evidence that it was water. It could have been, say, milk.
posted by brain_drain at 8:55 AM on May 31, 2013 [28 favorites]


Yes, we get it, space scientists. Mars once had water. Not hurry up and build a damn waterpark.
posted by bondcliff at 8:55 AM on May 31, 2013


SQUIRREL!
posted by Artw at 8:55 AM on May 31, 2013 [7 favorites]


Or, you know, blood.
posted by 2bucksplus at 8:56 AM on May 31, 2013 [10 favorites]


Tell Me No Lies: "The number of things that would have to happen to pull those elements together coincidentally is off the charts."

When talking about astronomy, one must consider that astronomical odds actually do occur...
posted by schmod at 8:56 AM on May 31, 2013 [9 favorites]


It could have been, say, milk.

Mars cocoa pebbles prove milk history
posted by It's Raining Florence Henderson at 8:57 AM on May 31, 2013 [11 favorites]


It's Raining Florence Henderson: "Mars cocoa pebbles prove milk history"

can't tell if Timecube or 1920s news headline
posted by lazaruslong at 8:58 AM on May 31, 2013 [3 favorites]


Squirrel milk.
posted by Artw at 8:59 AM on May 31, 2013


Man, some of you people are really jaded. Can't wait to see your reactions when the aliens arrive - "About time already, huh? What's the matter, get stuck in traffic?"

My five-year-old brain is going nuts over this stuff! We have the world's solar system's biggest R/C car driving around on another planet with camera taped to its back sending us back more data in a day than my childhood desktop computer could ever have handled comfortably! AND it used a fucking SPACE CRANE to get there! AND AND it's got LASERS on it! Shooting up rocks pew pew! And it even drew a penis in the dirt!

Any single one of these missions may as well be our civilization's Great Pyramid or Colossus or circumnavigation of the globe, and we're sending them out almost on a yearly basis. The mind boggles.
posted by backseatpilot at 9:09 AM on May 31, 2013 [54 favorites]


But will water on Mars leave the exact same kind of evidence as water on Earth? That is, won't gravity et al all change behaviour?
posted by infini at 9:13 AM on May 31, 2013


Gravity on Mars is 38% of what it is here, but that doesn't change the fact that water would flow downhill and carry suspended particles with it.
posted by Big_B at 9:17 AM on May 31, 2013


(also needs geology, curiosity, SCIENCE! tags)
posted by Big_B at 9:18 AM on May 31, 2013


Won't the speed change? Will less gravity pull the water flatter and shallower and wider?
posted by infini at 9:21 AM on May 31, 2013


(also also this FPP is talking about a published study of the previously published pictures.)
posted by Big_B at 9:21 AM on May 31, 2013


infini: "Will less gravity pull the water flatter and shallower and wider?"

Gravity is just a force, so I think it would only change the rate of flow (which would change the sediment loading capabilities). If you have a bowl of water on the Earth and the same bowl of water on Mars why would they behave differently?
posted by Big_B at 9:23 AM on May 31, 2013


At this point I will step aside for those with better memories of being a physics major, mine are three decades old and I don't have the information at my finger tips why I feel that changing gravity will have a greater impact than imagined.
posted by infini at 9:28 AM on May 31, 2013


Percival Lowell cackles with delight.
posted by dr_dank at 9:32 AM on May 31, 2013 [2 favorites]


I'm not trying to argue with you, I'm just not seeing it. Sorry if it appeared that way.

Here is the money quote from the paper:

The sedimentologic characteristics of these outcrops at Gale crater provide insights into sediment transport processes. Bedload collisional processes in flows produce rounding for heterogeneous clasts, and this is a particularly relevant mechanism for rounding the largest size fraction observed (pebbles with long axis of 10 to 40 mm). Sediment transported by traction (bedload) will slide or roll along the bed. Particles transported in a fluid are subjected to mechanical erosion, or abrasion, of the irregular edges of a particle through numerous impacts and grinding, ultimately producing a smooth surface.


So they are basically saying what all us geo-dorks have been saying ever since the pictures came out - the only process to achieve that sort of rounding on particles that size is through mechanical weathering which is generally fluid driven. Or a really big rock tumbler.
posted by Big_B at 9:34 AM on May 31, 2013 [1 favorite]


More impressive than there being water on Mars, then, is there having been water on Mars.

One step forward, etc.
posted by flippant at 9:42 AM on May 31, 2013


Second pic down in the original article looks like busted old concrete found in many older and slightly deteriorated cities/towns...

I'm not speculating any further, however.
posted by JoeXIII007 at 9:43 AM on May 31, 2013


The velocity of water flowing in a channel is a complicated function of a number of variables, including the channel's slope, something called the hydraulic radius of the channel, and another variable called the roughness coefficient which is a measure of the roughness of the channel sides and bottom. This roughness impacts the degree to which turbulent flow prevails. The lower gravity on Mars would enter into the equation through the slope variable--which was empirically derived here on Earth from analysis of various stream beds---i think
posted by Seymour Zamboni at 9:44 AM on May 31, 2013 [2 favorites]


If we're so fascinated by water on other celestial bodies, we should send a probe to Saturn's moon Enceladus. It's spewing water thousands of miles into space.

Instead, NASA continues its obsession with Mars.
posted by Brandon Blatcher at 10:21 AM on May 31, 2013 [2 favorites]


Is anyone else freaked out about this? What happened there? Liquid water can't exist there now. What were the circumstances that allowed it to exist back then, and why? What was going on on Earth back then? Could this happen to Earth and can we stop it? So many questions.
posted by drinkcoffee at 10:22 AM on May 31, 2013 [3 favorites]


Seymour Zamboni, what would have Bernoulli done?
posted by infini at 10:26 AM on May 31, 2013


Man, some of you people are really jaded

It is easy to take our scientific accomplishments for granted. So consider these animations of how the Mars Pathfinder landed on Mars and how the Rover Curiosity landed. Freaking amazing.
posted by Seymour Zamboni at 10:26 AM on May 31, 2013 [1 favorite]


drinkcoffee, their climate changed.

I am not sure why I feel like laughing hysterically right now.
posted by infini at 10:26 AM on May 31, 2013 [5 favorites]


Tell Me No Lies: "The number of things that would have to happen to pull those elements together coincidentally is off the charts."
When talking about astronomy, one must consider that astronomical odds actually do occur...


Indeed. But also that nature repeats herself endlessly from the spiral on your thumb to the cyclones on Jupiter to spiral galaxies.

When we look at those spirals we can make pretty solid guesses at the forces that create them. While the fundamental assumptions of cosmology are perhaps a greater leap of faith than any religion ever made, they have worked out pretty well so far and I'm comfortable saying the same forces that make a riverbed on earth made that riverbed on mars.

I'm not entirely convinced the fluid was water, but I'd bet a great deal of money that scene was produced by a river of something...
posted by Tell Me No Lies at 10:32 AM on May 31, 2013


Is anyone else freaked out about this? What happened there?

A popular theory is that Mar's liquid core cooled, which caused any existing magnetosphere it was producing to be "blown" away by cosmic radiation.

A magnetosphere is what keeps cosmic radiation away from Earth's surface and atmosphere, allowing weather and life to flourish. It's generated by the hot liquid interior of the planet moving around a solid core, which generates a magnetic field.
posted by Brandon Blatcher at 10:37 AM on May 31, 2013 [3 favorites]


I keep thinking of writing a short story where say 15 years from we land on Mars and find artifacts of a civilization that bogarted a billion years of organic carbon into their atmosphere and destroyed their ecosystem, right as, say, our west antarctic ice sheet collapses and slides into the ocean.
posted by crayz at 10:42 AM on May 31, 2013 [3 favorites]


But what else would the aliens drink?
posted by 0 answers at 10:43 AM on May 31, 2013


What was going on on Earth back then?

At 3 billion years ago, the earth already had oceans and clouds and microorganisms capable of photosynthesis were pumping out oxygen. But that oxygen was used to oxidize iron in the environment, forming the large banded iron formations that we are still mining today. And then once most of the iron was oxidized, oxygen was free to accumulate in the atmosphere in greater amounts. And the rest is history! Not sure about Mars back then however.
posted by Seymour Zamboni at 10:53 AM on May 31, 2013 [2 favorites]


Gravity and a magnetosphere are useful things when you want to keep ahold of an atmosphere.
posted by Devils Rancher at 10:55 AM on May 31, 2013


The problem is not so much radiation as the solar wind, which can accelerate molecules at the outer edge of the atmosphere to escape velocity and slowly blow the whole atmosphere away over aeons. The magnetosphere deflects the solar wind, which consists of charged particles, so that it mostly bypasses the actual planet.

Being geologically active the Earth also replenishes its atmosphere by venting gases from the planet's interior.

The freezing up of Mars' core stopped both mechanisms, so its apparently once fairly thick atmosphere got blown away.

Since much of the geologically added atmospheric gas is carbon dioxide, if nothing ever removed it a greater danger would have been turning into Venus. Fortunately the Earth also has this stuff called "life" which plays a very active role in managing the composition of the atmosphere.
posted by localroger at 10:59 AM on May 31, 2013 [1 favorite]


0 answers: "But what else would the aliens drink?"

Romulan Ale?
posted by Big_B at 10:59 AM on May 31, 2013 [1 favorite]


Their smooth appearance is identical to gravels found in rivers on Earth.
How could these so-called "scientists" ignore the obvious? Ancient aliens must have picked up some gravel while they were hanging out in Egypt and dropped it off in Mars.

What, the riverbed of the Nile is full of fine-grained sand? There aren't any smooth pebbles for hundreds of miles of the Egypto-Alien necropolis? Um... Rushes back to consult the TimeCube
posted by b1tr0t at 11:01 AM on May 31, 2013


That's also 3 billion years of sand-blasting sandstorms. Couldn't that also have the same effect?
posted by jabah at 11:03 AM on May 31, 2013


Nah, it was liquid methane, from back when Mars was a moon of Saturn. It lost its atmosphere when it was potted into a near-Earth orbit on a three-bank shot in the Solar Billiards championships of Galactic Year 704Z.
posted by George_Spiggott at 11:03 AM on May 31, 2013 [3 favorites]


That's also 3 billion years of sand-blasting sandstorms. Couldn't that also have the same effect?

Rocks sandblasted by wind on Earth are called ventifacts. There is a smoothness too them but they also have a unique ridged shape that imparts some angularity as well. So maybe a particle shape analysis has been done to rule that option out?? Not sure.
posted by Seymour Zamboni at 11:07 AM on May 31, 2013 [1 favorite]


0 answers: "But what else would the aliens drink?"

Ask Draco.

Rocks sandblasted by wind on Earth are called ventifacts. There is a smoothness too them but they also have a unique ridged shape that imparts some angularity as well. So maybe a particle shape analysis has been done to rule that option out?? Not sure.


*sounds klaxon*

Different operating environment. Alien. Not like Sting in New York but a HeeChee or somesuch.
posted by infini at 11:13 AM on May 31, 2013 [2 favorites]


Rocks sandblasted by wind on Earth are called ventifacts.

I thought that was what Cracked list articles are called in Italy. Either that or informational brochures about tallish Starbucks coffees.
posted by George_Spiggott at 11:25 AM on May 31, 2013 [3 favorites]


Universe-expanding news. It always amazes me that this stuff receives so little mainstream media coverage, that it has to struggle for space.
posted by thesmallmachine at 11:48 AM on May 31, 2013


A really neat piece of work - pretty much cinches down the water hypothesis.
Couple of minor points:
Using its Chemcam remote-sensing laser, the rover was able to detect feldspar in the lighter toned clasts.
Yes - excellent!
Feldspar is a common mineral on Earth that weathers quickly in the presence of water.
Well.. Not really quickly otherwise the the Rockie Mountains would be known as the Great Gritty Sludge Pile.
(Yes - geologic time scale etc etc. Even then not really quickly.)
This suggests past conditions were not overly wet
"Overly"? It had to be pretty darn wet to produce those sediments and the presence of feldspar minerals is not an indicator of dryness.
and that the pebbles were carried only a relatively short distance - probably no more than 10-15km
Yes! And next? Locate the source rocks! :)
posted by speug at 11:56 AM on May 31, 2013 [2 favorites]


Being married to a NASA programmer killed the romance of space science for me in a lot of ways, but this sort of story makes me feel like an excited little kid again, especially reading the science nerds here discussing the research and next steps and all that.
posted by immlass at 12:05 PM on May 31, 2013 [1 favorite]


*buttered risotto* immlass, btw do u kno mohawkguy?
posted by infini at 12:07 PM on May 31, 2013


iO9 really dropped the ball by not making a Giant Space Hamster joke with that one.

This is pretty neat though! I've been reading a lot of sci-fi with people settled on Mars and it's nice to know that we live in the future in real life too.
posted by NoraReed at 12:39 PM on May 31, 2013


speug: "Locate the source rocks!"

THIS! But I imagine they're gone. However this is a good point of study that is getting lost in the excitement - The Mars Rock Cycle!
posted by Big_B at 12:40 PM on May 31, 2013 [1 favorite]


Mars pebbles alone don't "prove" anything. They suggest that some force -may- have pushed the rocks along, 'weathering' them through abrasion.

Crappy science journalism aside, we have to remember that the strong wish to find evidence of water on Mars influences the interpretation of these observations. That's not science.
posted by Twang at 12:46 PM on May 31, 2013


So maybe a particle shape analysis has been done to rule that option out?? Not sure.

They've got to have specialists in just that sort of stuff crawling all over the data coming out.
posted by sebastienbailard at 1:01 PM on May 31, 2013


Oh just stream it raw open data straight into our gaping maws already.
posted by infini at 1:07 PM on May 31, 2013 [1 favorite]


Twang, unless you have a hypothesis for a 'force' that isn't water, then you are doing sourceless contrarianism, not science. From the size and pattern of abrasion, you can determine the characteristics of the force, and from the arrangement of the deposits, you can learn even more; glaciers drop in a different pattern than streams. There's not a candidate 'force' that fits the conditions that would have existed on Mars, except liquid water. That's not even getting into the chemical record available from the types of minerals produced and how they reacted.

There's certainly an ongoing debate as to how long and often the liquid water flowed, but there's not much debate at this point about there being liquid water.
posted by tavella at 3:26 PM on May 31, 2013 [4 favorites]


There's not a candidate 'force' that fits the conditions that would have existed on Mars, except liquid water.

TEACH THE MILKTROVERSY
posted by Rock Steady at 8:37 PM on May 31, 2013 [4 favorites]


If you put milk under a pyramid it doesn't go off - THINK ABOUT IT.
posted by Artw at 8:46 PM on May 31, 2013 [2 favorites]


Second pic down in the original article looks like busted old concrete found in many older and slightly deteriorated cities/towns...

I'm not speculating any further, however.


I will. A lot of Mars rocks look like terra-cotta. (marsa-cotta?)
posted by gjc at 11:18 PM on May 31, 2013


RICKcotta
posted by infini at 1:29 AM on June 1, 2013


"Being married to a NASA programmer killed the romance of space science for me in a lot of ways..."

...Can ...can I have him then? Because I'm pretty sure that being married to a NASA programmer would have the exact opposite effect on me.
posted by Blasdelb at 9:44 AM on June 1, 2013 [1 favorite]


...Can ...can I have him then? Because I'm pretty sure that being married to a NASA programmer would have the exact opposite effect on me.

I think he's still married to his third wife, alas. (and sadly, no, I don't know Mohawk Boy, who seems awesome.) The downside of hearing the at-work stuff is that not enough of it is AWESOME SCIENCE! and too much of it is bureaucratic budget wrangling and the like.
posted by immlass at 10:26 AM on June 1, 2013 [2 favorites]


Can our heartfelt geeking out help bring some sparkly romance back into your thoughts per haps?
posted by infini at 10:33 AM on June 1, 2013


Dyna-Soar’s Martian Cousin: Bono’s Mars Glider (1960)
posted by the man of twists and turns at 9:36 PM on June 1, 2013


Bradbury Landing. So cool.
posted by Smedleyman at 9:41 PM on June 1, 2013


drinkcoffee, their climate changed.
I am not sure why I feel like laughing hysterically right now.
Dunno, but that comment made me laugh hysterically just now. Thanks for that!
posted by StrawberryPie at 9:18 AM on June 2, 2013


Evidence Of Potentially Drinkable Water Found On Mars
posted by homunculus at 1:39 PM on June 9, 2013


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