exciting times we live in
Super cool - were I one of the Dirt People, I'd want to be working on this stuff.
The Martian nuclear truck Curiosity has found further evidence that water once flowed freely on the Red Planet's surface. Martian rocks compared with ones on Earth Boffins' initial theory that pebbly beaches on Mars indicate ancient streambeds has been borne out by detailed analysis of the pebble-containing slabs spotted by …
Super cool - were I one of the Dirt People, I'd want to be working on this stuff.
They carefully avoided the word "water", at least as El Reg reports the new.
All they say is that "a sustained flow" rounded stones corners.
Could have been another solvent; every river is not water in our Universe.
Like a river of flowing of sand, as in a sand-storm, for example...
Dead right. Imagine the excitement if the fluid turned out to be alcohol (how easy would it be to get volunteers for a trip to Mars then?).
Alternatively, it was octane, and some Martian equivalent of the Humvee became so popular that they used every last drop (hence the carbon-dioxide atmosphere).
An interesting idea.
What other solvent would you suggest, that is abundant in our solar system, liquid in the temperature range likely to have existed on Mars in the past, and chemically consistent with the composition of the rocks in question, and the planet as a whole?
The only substance I can think of (and I hold two Chemistry degrees) is good old H2O. Of course, the Devil lies in the detail, and just becuase there is evidence for abundant flowing water, it doesn't mean that it is pure water, it could be anything from brine, like the oceans here on Earth, to strong acid or alkali, as found in some volcanic systems, or cave systems. Given the atmospheric conditions at the time, it could contain oxidants, or reducing agents. Water, after all, does make a good solvent for a lot of things.
You will probably find that pebbles are not rounded by these.
And that's the point: when does it stop being "water" and start being something else in solution. Would your really call a solution of 30% sulphuric acid "water"? Caution is to be commended until it's firmly established this was something a lay person might call "water".
Dry lahar flows produce the same results as wet rivers but without the particle size separation - exactly what we see here. We dont see them too often on earth because its too wet but Mars does look like a good place to find them.
Get permission to have "rounded corners"
The grains in lahar deposits are only occasionally sorted and it would be very unusual for lahars to be interspersed with fine grained sandy deposits; whilst it is quite common in rivers.
NASA called it 'water' in their press release...
A real scientist will go on arguing until he or she is satisfied by the proofs/arguments given (and even then could start arguing again as new data become available).
Damn! You beat me to it.
No: sand rounded rocks are different in topology. Much rounder and smoother.
As I recall, many explanations I've heard for deposits/formations like these on Mars which don't involve liquid water usually involve flows of liquified carbon dioxide. Don't forget it's really friggin' cold on Mars.
Still, given the age of the gravel and sand deposits and other suggestive features, it really would be cool if they finally determined once and for all that it was caused by flowing liquid water.
Don't forget the fotos from the surface of Titan, where ice takes the place of rock, and there's a meteorological cycle similar to Earth's water cycle, only based on liquified hydrocarbons. As I recall, the fotos from the Huygens probe's descent showed channels, valleys, river deltas and other features that looked remarkably like similar features carved out by flowing water on Earth; fotos from the surface showed ice "rocks" resembling rounded smooth stones tumbled by flowing water on Earth.
Still, it'd be way cool if it really did turn out to be due to water on Mars.
I can think of a half dozen solvents common in the solar system that could perform the same function. However, as you say, under martian conditions, the list narrows to essentially one. Water.
Add in the layering that occurred that can only be accounted by higher mass flow, not atmospheric flow, it ends up being water.
Unless someone suddenly finds a highly probable theory where Mars started out far beyond the frost line!
To give away a bit of my age, my high school chemistry teacher used to refer to water as the universal solvent.
As for martian environment being oxidative or or reductive, that depends on the chemistry of the various strata. Something I'm uncertain we can fully gather with the tools currently on Mars. We can only attempt to deduce, based upon what is found on or very near the surface.
"Would your really call a solution of 30% sulphuric acid "water"? "
Yes, acidic water. For, it'd be nearly 70% water and various solutes and reactants.
@Tom 7, quite true. On Earth, we see such in deserts, in China, in the US and in both Africa and the Arabian peninsula for common areas that they're observed.
One also has to account for lower atmospheric pressure and lover gravity when accounting for any form of fluid flow, be it atmospheric or a liquid medium, such as water.
Liquified CO2 requires a lot more pressure than could ever be attributed to Mars, with its humble gravitation.
The only way CO2 could flow as a liquid on Mars would be if it were carbonic acid, which requires water to exist.
Comparing these stones to earth material I would comment that the degree of rounding indicated many tens of thousands of impacts such as might be encountered on a shoreline with wave action. I don't think a trip down a short steam would be enough. Of course the water could be aggressive; on the other hand one has to consider that Martian gravity is a lot less than earth and the wear rate would correspond.
Just like a proper English beach!
No, it's not raining...
Only you'd get through a shitload more ice cream before the tide comes in.
It might not be raining. But it's freezing cold, so you can't get out of the car anyway. So we're talking Skegness.
"What other solvent would you suggest, that is abundant in our solar system, liquid in the temperature range likely to have existed on Mars in the past, and chemically consistent with the composition of the rocks in question, and the planet as a whole?"
"Freeeow," he said. He took another sip of water, then held it up to the light and frowned at it. He twisted it round.
"Hey, is there something in this water?" he said.
"Er, no, m'lud," said the Court Usher who had brought it to him, rather nervously.
"Then take it away," snapped Judiciary Pag, "and put something in it. I got an idea."
I think their white balance is off. That picture on the left is weighted pretty heavily toward red.
The fotos which appear to have a heavy reddish cast are actually the natural colors, pretty much the way our own eyes would see that scene were we lucky enough to go to Mars.
If you go to the MSL Web site, they post the natural color fotos alongside versions which are color-adjusted to simulate viewing conditions on Earth. Purely aesthetically speaking, I prefer the "raw" natural color versions as they're more like being there.
But when you adjust the colours the similarity between the two pictures is much more striking, and, the colour-corrected version does probably show how the same patch of Martian ground would look under the Earthly lighting conditions.
That's foundation concrete (I'm sure it has a technical name, but I mean the stuff that's cement mixed with whatever stones they can find locally, used for laying roadbeds and similar).
Might they not find more evidence of water by analysing the gravel suspension (cement) rather than the stones themselves? Any concrete experts out there care to comment?
Aggregate concrete and yes it does.
that pebbles were round as they abraded against each other, not by pure water (liquid) action?
Paris, as she's great for abrasion!
Yes, but it's the water's motion that causes the stones to abrade against each other.
Apparently 1cm on Mars is more than twice the size of that on Earth.
The technical term for that is "redshift". Google it.
"Their rounded edges are typical of wee stones"
Is it kidney problems that make the little men green, then?
"Rounded pebbles suggest that, at some indeterminate point in the very distant astronomical past, there might have been something liquid flowing on the surface
What does this prove? Nothing.
Nothing to see here, move along.
It's called river stone and that's EXACTLY what it looks like.
He's probably never been outside, don't be too hard on him.
> It's called river stone and that's EXACTLY what it looks like.
River of what? Water? No proof it was water. Could have been some other liquid. How long ago was it flowing? Unknown. What was it? Unknown.
Every single time Congress is starting debate on next year's budget, NASA releases some buzzwordy irrelevant speculation photo about what might have occurred on Mars 2 billion years ago. Why is speculation about 2 billion old hyopthetical events relevant to anything today beats me.
The only object in the Solar System for which there is undisputable evidence of stable bodies of liquid at the surface is Titan, one of Saturn's moons. And it's not water.
Are those Google Glasses in your icon?
Imagine how long it took the Martians to smooth out the corners on all those pebbles, and then bind them together and place them so they would look like a riparian deposit. Can Opportunity's spectorgraph detect paste residues??
Clearly it wasn't Martians doing that stuff. It was God, probably four to five thousand years ago, at exactly the same time as He created the rest of the universe. The evidence is clearly and unequivocally left on Mars for us to discover, so we can be so confused by this so called 'science' that we stop wondering about this stuff and accept that all the answers are right there for us in the King James Bible. We need to stop going to Mars etc, and go back to burning heretics and wearing hessian undergarments.
...but not a drop to drink(see).
When they drill and get a gusher, that will be VERY exciting!
I wonder if the Martians did that too.
I'd like to see someone using a stone to skip across the water! I can only manage to skim the stone itself.
Google image and compare.
Dammit, got to read some Asimov again.