From NASA’s Jet Propulsion Lab, some exciting news of the “picture is worth a thousand words” variety – NASA Rover Finds Old Streambed on Martian Surface
Scientists are studying the images of stones cemented into a layer of conglomerate rock. The sizes and shapes of stones offer clues to the speed and distance of a long-ago stream’s flow.
“From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep,” said Curiosity science co-investigator William Dietrich of the University of California, Berkeley. “Plenty of papers have been written about channels on Mars with many different hypotheses about the flows in them. This is the first time we’re actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it.”
The finding site lies between the north rim of Gale Crater and the base of Mount Sharp, a mountain inside the crater. Earlier imaging of the region from Mars orbit allows for additional interpretation of the gravel-bearing conglomerate. The imagery shows an alluvial fan of material washed down from the rim, streaked by many apparent channels, sitting uphill of the new finds.
The rounded shape of some stones in the conglomerate indicates long-distance transport from above the rim, where a channel named Peace Vallis feeds into the alluvial fan. The abundance of channels in the fan between the rim and conglomerate suggests flows continued or repeated over a long time, not just once or for a few years.
The discovery comes from examining two outcrops, called “Hottah” and “Link,” with the telephoto capability of Curiosity’s mast camera during the first 40 days after landing. Those observations followed up on earlier hints from another outcrop, which was exposed by thruster exhaust as Curiosity, the Mars Science Laboratory Project’s rover, touched down.
“Hottah looks like someone jack-hammered up a slab of city sidewalk, but it’s really a tilted block of an ancient streambed,” said Mars Science Laboratory Project Scientist John Grotzinger of the California Institute of Technology in Pasadena.
The gravels in conglomerates at both outcrops range in size from a grain of sand to a golf ball. Some are angular, but many are rounded.
“The shapes tell you they were transported and the sizes tell you they couldn’t be transported by wind. They were transported by water flow,” said Curiosity science co-investigator Rebecca Williams of the Planetary Science Institute in Tucson, Ariz.
The science team may use Curiosity to learn the elemental composition of the material, which holds the conglomerate together, revealing more characteristics of the wet environment that formed these deposits. The stones in the conglomerate provide a sampling from above the crater rim, so the team may also examine several of them to learn about broader regional geology.
The slope of Mount Sharp in Gale Crater remains the rover’s main destination. Clay and sulfate minerals detected there from orbit can be good preservers of carbon-based organic chemicals that are potential ingredients for life.
“A long-flowing stream can be a habitable environment,” said Grotzinger. “It is not our top choice as an environment for preservation of organics, though. We’re still going to Mount Sharp, but this is insurance that we have already found our first potentially habitable environment.”
During the two-year prime mission of the Mars Science Laboratory,esearchers will use Curiosity’s 10 instruments to investigate whether areas in Gale Crater have ever offered environmental conditions favorable for microbial life.
NASA’s Jet Propulsion Laboratory, a division of Caltech, built Curiosity and manages the Mars Science Laboratory Project for NASA’s Science Mission Directorate, Washington.
For more about Curiosity, visit: http://www.jpl.nasa.gov/msl , http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl .
You can follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity .
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If Curiosity finds some gold in that old stream bed, you know there will be a manned mission to Mars…gold fever and “go fever” are two strong forces for accelerating exploration, combined they’ll be irresistible.
Friends:
I write to provide thanks to all who have attempted to answer my question. I hope others will also try to help my understanding.
I am minded that confirmation bias is always a problem which is difficult to avoid.
I am material scientist who is very familiar with wear in fluidised beds so when I look at that photograph I see what looks like a slumped fluidised bed. Indeed, what I am seeing on that photograph looks very like a slumped fluidised bed. This is possibly my confirmation bias: I see what I know.
And I have seen videos of fluidised beds with high flow rates happening naturally on Earth; i.e. pyroclastic flows from volcanoes and Alpine avalanches. So, I find no difficulty imagining such fluidised beds running across the surface of Mars with its lower gravity and higher wind speeds.
You geologists helping me to learn about this Martian deposit are very familiar with sedimentary deposits. When you look at the photograph you see what looks like a sedimentary deposit. And your knowledge of geological processes is much greater than mine will ever be, so your interpretation is probably right. But, of course, you may have a confirmation bias, too.
Your responses to me have all been considered, helpful and informative. I am truly grateful for each of them. But, so far, your responses amount to “It looks like a duck” when I am saying “It looks like a goose”. I would like a response akin to “It quacks like a duck, and does not honk like a goose”.
Richard
Temperatures on Mars range -87 to 0 degrees C. How does water form and flow in an environment like that?Could this be super-well-preserved 5 billion year old remains from the heat of planet formation, or a giant solar flare or something?
Given mars’s low gravity, and thus low air pressure, how long can water remain liquid?
Should we be imagining that mars at one time had roaring rivers and huge lakes? Or did the water boil off as soon as it seeped out of the ground? Or what?
Tony Mach:
At September 28, 2012 at 3:48 am you write
With respect, it does not need to be a liquid: it needs to be a viscous fluid.
This is why I am asking the geologists to try to educate me as to why the pebbles were not “rounded” by an abrasive fluid bed of sand that is fluidised by the Martian CO2 atmosphere flowing (or successively flowing) across the Martian surface.
Please note that such a fluidised flow would be much more abrasive and erosive than a flow of water.
Richard
Fantastic! And fun to see the Geologists on WUWT have a subject they can work. I think it looks like typical water transported worn cobbles. I’ve seen enough of those having spent 4 weeks mapping geology out in the Imperial Formation by Anza Borrego. Windblown sand eroded cobbles have distinct scaloping – i see a lot of that on hikes in the surrounding hills. And sand blasted and chemically etched beer bottles that are extraodinarly beautiful objects considering their humble origins. I do question the statement – “Gravel fragments are too large to be transported by wind. “. Up here in the north Mojave we have our “3/4 inch” days when wind blown pebbles take out your windshield! On those days it’s best to stay home and wonder when the roof is going to go.
I’m not sure this has merit, but have been reading in a few places that NASA has photo-shopped some of the photos of Gale Crater. What do you think? Possibility or hoax?
http://www.earthfiles.com/news.php?ID=2015&category=Science
richardscourtney says:
September 28, 2012 at 1:28 am
Friends:
There you go, experience is worth more than a science degree!
Kelvin Vaughan:
Please explain your ridiculous comment at September 28, 2012 at 6:45 am which has no relationship of any kind to my post which you cite.
Richard
Obviously Mars’ atmosphere and all water was destroyed by global warming brought on by all those bloody SUVs http://upload.wikimedia.org/wikipedia/commons/thumb/d/d8/NASA_Mars_Rover.jpg/250px-NASA_Mars_Rover.jpg
All those SUV’s on Mars sure have caused some climate change!
Is the con-spira-acy industry alive and well or what?
If a simple, Occam’s Razor-class explanation (e.g. a simple mistake by NASA in labeling pics) develops please, by all means, keep us informed.
.
Writes Anthony:
I have long said that if we find gold on the Moon, we’ll be back there in a heartbeat. Same goes for the rest of the Solar System, though it may take two or three heartbeats. Nothing like a little economic incentive to spur exploration—and settlement.
Recommended reading: John Lewis, Mining The Sky: Untold Riches From The Asteroids, Comets, And Planets: http://www.amazon.com/Mining-The-Sky-Asteroids-Planets/dp/0201328194
I know nothing of geology, but my first reaction was similar to Richard Courtney’s: winds on Mars are fierce, sandstorms common, and a strong-enough wind can lift even a good-sized pebble. However, I think they are saying that the bed of pebbles fragmented off the conglomerates. Wind and sand could have done that, but could the conglomerates have formed outside of water?
Does Curiosity have equipment that would enable its handlers to determine how old those conglomerates are?
/Mr Lynn
[snip . . not funny, or clever . . mod]
An, an, and if they don’t start to listen to me soon I’ll hold my breath until I make myself sick.
THEN I’ll launch an on-line survey !!!!!
KevinM asked “Temperatures on Mars range -87 to 0 degrees C. How does water form and flow in an environment like that?”. Simple answer – medieval warm period!
A streambed? Good. We found out what happened to a cat on Mars. Maybe now we can find out about the catfish!
@richardscourtney
“This is why I am asking the geologists to try to educate me as to why the pebbles were not “rounded” by an abrasive fluid bed of sand that is fluidised by the Martian CO2 atmosphere flowing (or successively flowing) across the Martian surface.”
That is a possibility. Outside my experience, but I haven’t done a lot of field work on Mars. Flow regime is a vast subject, from rockfall at one end to anastomosing rivers at the other. It is complicated by the probabilty that within a given system, you will find incorporated clasts that have been shaped in another (inheritance). Sometimes there are no easy answers.
One thing experience has taught me is that normally you can’t solve “the problem” from one exposure. As I mentioned above, I would like to see much more comprehensive sections in order to have any confidence in a given interpretation.
Don’t underestimate the abrasiveness of stream flow. It’s not just water moving, but the bedload and suspended load too. In mountain valleys, for example, you can find nicely rounded outcrop and boulders that haven’t moved very far at all.
In short, nice image but not definitive.
[snip . . mod]
I bet they think if they told us that CO2 could… no well maybe that’s going a bit far.
If the mars landings were faked, then climate change is not happening. Maybe we need a survey….
“But what other potentially liquid substances are there on Mars to account for this? ”
umm.. do you mean liquid, or fluid ?
very fine dust suspended in rivulets of air is a possibility, maybe?
I do not know if I am wrong about this , but I remember being told a decades or two ago that the stuff that the colour of Marz was mainly caused by the fact that its surface material had a high content of ferrosulfid and remember thinking “ah so it is an hell of rustheap , maybe the biggest one in ever seen the neighbourhood ” and then surmising that it must have had at least some water (and maybe an hell of a lot of it ) , because the only process I knew of that could make Iron rust requier’s , that it is in some contact with water (liquid or gaseous ). This was a few years before NASA managed to land a crawler there , and the guy who told this snippet about the ferrosulfid said this fact came from a number of spectroscopic analysis of light reflections from itś surface, and I was not intrested enough to try to verify his word about this, just took it as good solid truth. I do not know if it still holds or if the rovers have found the surface to be something else than rusty,in fact I have not given this any thought for quite a number of years, but if marz is really rusty , the I think it lends some credence to the hypothesis that it was also a little wet onse upon a time.
P. Solar says: “The 100 mph winds will soon be common place on Earth too. ”
Oops, I just checked with Professor Yackel, expert climatologist/geologist at U. Calgary, and that should have read “one million mph winds”. My bad. 😉
Proof of water on Mars.
This stream bed doesn’t appear to be any different from those seen in many years of photos from the other Mars rovers. Some even show puddles and recent flow, i.e. hrs vs. “millions” of years here. If you can believe it, there are photo’s from orbit of ponds and lakes, apparently unfrozen.
Remember, the comments are from Never A Straight Answer/JPL.
This is why I come to WUWT.
cn
…with my emphasis on repeated
Hmmm. Episodes of ice sheets on Earth, floods on Mars…