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Ancient stream bed on Mars
September 29, 2012 12:31 AM   Subscribe

Curiosity has been on Mars for 51 sol-days and today NASA announced it has found what looks like a concrete slab made up of rounded stones which is probably an ancient stream bed formed by hip-deep fast-moving water over thousands or millions of years. Observers have long hypothesized the canyons and river-like beds photographed from space were carved by water, but only now do researchers have on-the-ground confirmation for the first time.
posted by stbalbach (71 comments total) 21 users marked this as a favorite

 
The NASA video is long but there is good stuff from about 9m50s -> 15m50s
posted by stbalbach at 12:33 AM on September 29, 2012


Project scientist John Grotzinger told reporters scientists already were virtually certain that water flowed into Gale Crater in the distant past based on orbital photographs showing what appeared to be an alluvial fan spreading out from the crater rim. Curiosity landed on the floor of the broad crater Aug. 6

But seeing such a structure from orbit is one thing. Seeing the actual rocks made up of debris that was once swept along shallow channels making up the fan is gratifying to the science team because it provides "ground truth" for the observations made from orbit and shows Curiosity landed in a scientifically rich site.


Seeing actual rocks made up of debris that was once swept aling shallow channels making up the fan is one thing. I will withhold making conclusions until I see photographic evidence of an old car tire stuck in the Martian mud.
posted by three blind mice at 12:53 AM on September 29, 2012


I overheard that Curiosity also found and terminated a feline lifeform. Is that right?
posted by iotic at 1:11 AM on September 29, 2012 [34 favorites]


Science by press release is not science. There are reasonable alternative explanations (this one hinges on the roundedness of the clasts). There are a ton of talus slopes on mars, why not a chemically welded talus breccia (like a caliche)?
posted by grajohnt at 3:49 AM on September 29, 2012


Oh man, I am so tired of the never-ending battle of water vs Mars.

At this point, we've had dozens of "proofs" that water existed there. Each one has an alternative explanation. But isn't the simplest overarching theory that water existed there? Otherwise we have to have all these other things that happened to perfectly simulate the existence of water. It's not like the claim needs extraordinary evidence. It's hardly supernatural to think there might once have been water on a planet very near Earth in sun-distance, size, etc.
posted by DU at 3:59 AM on September 29, 2012 [7 favorites]


Science by press release is not science

You're young, aren't you? Ever heard of "Mercury"? "Gemini"? "Apollo"? Press releases were an important part of the science. It's called "funding". You may wish to adjust your opinions on the importance of press releases.
posted by Goofyy at 4:06 AM on September 29, 2012 [14 favorites]


iotic: I overheard that Curiosity also found and terminated a feline lifeform. Is that right?

Not completely. Their was a stitch in time and it saved nine.
posted by Skygazer at 4:39 AM on September 29, 2012 [3 favorites]


I overheard that Curiosity also found and terminated a feline lifeform. Is that right?

Yes.
posted by ryoshu at 4:40 AM on September 29, 2012 [1 favorite]


NASA to do list :

1) Prove water used to be on Mars : check
2) Profit !!!

I love NASA and Mars and Water and stories about Mars but discovering something that is not there anymore seems more like history than science to me at some point.

Its like discovering I used to have orange juice in my fridge , okay now what ?
posted by epjr at 4:44 AM on September 29, 2012


Unfortunately if it finds an entrance to the immense cavern with the ancient alien lever that will return the water and atmosphere the line of sight will be cut off and the scientists will not be able to control it.
posted by sammyo at 5:10 AM on September 29, 2012 [1 favorite]


Its like discovering I used to have orange juice in my fridge , okay now what ?

Look for evidence of organisms that may have been living in your orange juice.
posted by RobotVoodooPower at 5:22 AM on September 29, 2012 [32 favorites]


but discovering something that is not there anymore seems more like history than science to me at some point.

Figuring out the how and why of the disappearing water is the science.
posted by Brandon Blatcher at 5:27 AM on September 29, 2012


Well, it would be kind of hard to have liquid water with those −55 °C temperatures. There is plenty of ice on mars. One of the major problems is that the gravity wasn't strong enough to hold Mars's atmosphere forever, which of course meant no greenhouse effect, and so on.
posted by delmoi at 5:37 AM on September 29, 2012


discovering something that is not there anymore seems more like history than science to me at some point

Like a sizeable chunk of astrophysics? I don't really understand the distinction you're making. The data aren't 'science data' or 'history data', science and history are practices applies to data. Also, when did history become unimportant?
posted by howfar at 5:38 AM on September 29, 2012 [1 favorite]


It's a particle of mounting evidence that supports other observations. These observations and explanations don't yet conclude anything, but for the life of me, why is this even a point of contention? There's an apparent alluvail fan. Apparent water channels. Apparent sedimentary rock. Apparent shorelines. Definite water ice at the poles.

The HOPE, of course, is that there's a nice little fossil exposed somewhere. Failing that, a nice little micro-fossil or chemical bio-marker which will support the perfectly reasonable hypothesis that there is extra-Earth life 'out there', and take the steam out of exclusive Earth-centric fables about our species. For me, anyway.

Knowledge is a threat to faith. Perhaps that's why this topic elicits such conflict.

One might want to consider that there is a rover ON MARS at this moment, landed there by humans, engineered and executed with the same science methods that are interpreting the instrumentation's observations. Armchair quarterbacking the scientific implications when the best most humans can do is find their butts with both hands is just sad.

Reminds me of Boy Scouts playing war.
posted by FauxScot at 5:42 AM on September 29, 2012 [12 favorites]


Much of Geology looks at the "history of rocks", it is science.
Much of Climatology looks at the "history of climate indicators", it is science.
Much of Biology looks at the "history of species", it is science.

Not everyone can design futuristic robits; which is also science (almost nothing about this/what NASA does is not part of the scientific process).
posted by infinite intimation at 5:55 AM on September 29, 2012 [1 favorite]


I've always wondered....when they say "water" do they mean actual water, H2O? Or do they mean liquid? Is it possible that some ghastly chemical in liquid form could have flowed over the surface of Mars and had the same effect? Is this just wishful thinking? Are they so desperate to find actual water on another planet that they're overlooking a past Colorado River of ammonia or something that carved canyons?
posted by nevercalm at 6:03 AM on September 29, 2012


They mean real water.
posted by ryanrs at 6:35 AM on September 29, 2012 [1 favorite]


Yeah, there's not a huge ton of possible elements that would have existed in liquid form at Mars temperatures other than water.
posted by Devils Rancher at 6:39 AM on September 29, 2012


A decent proportion of the rocks found by the Opportunity rover that were cited as evidence for past water were ones whose equivalents on Earth are nearly always formed in the presence of liquid H2O. Much of the analysis of the martian rocks has been based on drawing parallels between what we've found on Mars, and similar rocks that we find on Earth, for which geology has a pretty good idea of the conditions in which they formed.

There's always going to be the possibility that there's some other non-water explanations for certain rock formations, however as different pieces of evidence start to come together, the historical presence of water on Mars is starting to become the simplest coherent explanation that covers all the disparate bits of data that we've found.

There's also the possibility that there are intermittent flows of liquid water on the surface of Mars in the present day. Given that they're absent from prior photographs of this same crater, these gullies must have been formed at some point between 1999 - 2004. The low atmospheric pressure would ensure that liquid water would indeed evaporate away very quickly (hence their being intermittent flows instead of streams or lakes)

Getting close to proving the presence of historical water would be an exciting discovery. Finding present-day liquid water would be amazing. I have a small hope that they might locate a subglacial lake underneath the Martian icecaps - something similar to Lake Vostok in Antarctica. If it were buried deep enough, the pressure from the mass of ice above would be more than enough to counteract the low atmospheric pressure, might might allow for liquid water.
posted by talitha_kumi at 6:41 AM on September 29, 2012 [2 favorites]


Press releases were an important part of the science. It's called "funding". You may wish to adjust your opinions on the importance of press releases.

Yes, but, remember cold fusion and that fateful press conference in 1989 that effectively ended the career of two well regarded chemists? I think the general point is that scientific claims announced through the press are highly contingent (and potentially ruinous) until peer review takes place.

There are a ton of talus slopes on mars, why not a chemically welded talus breccia (like a caliche)?

Breccias have angular fragments. The observed rock layer doesn't look like a talus breccia to me. But then again the distinction between angular and rounded rock fragments is highly subjective at some point. And I believe all chemical models for caliche formation still involve water as the medium that causes leaching and subsequent precipitation of CaCO3 in soil layers. And chemical cements within sedimentary rocks involve chemical precipitation of various compounds from pore waters. So I guess it is hard to explain the observed rock without calling on the action of water in some way--if we extend earth based models of rock formation to other planets.
posted by Seymour Zamboni at 6:43 AM on September 29, 2012 [1 favorite]


We're on vacation in the (U.S.) desert southwest, driving around looking at rocks. We've seen evidence of the radically different ways landscapes can be affected by water (frozen and flowing) - Zion, Bryce, Arches, Canyonlands, and Monument Valley all look pretty different from on another, and all got a lot of help from water/ice in their formation. Are still getting, I should say. It's all kinds of amazing.
posted by rtha at 6:45 AM on September 29, 2012 [2 favorites]


Pretty obviously remnants of a statue of a sacred alligator. If NASA hadn't immediately gone into cover-up mode and cropped the picture, I'm certain we would have seem ruins of an entire temple complex. My website will soon have a reconstruction of the suppressed photos, a petition demanding NASA end the cover up and return Curiosity to the site immediately for an honest, open investigation, and a link to Amazon where you can buy my book explaining daily life of those who served the alligator gods and why the entire complex points precisely at Tenochtitlan every third Solstice and how the technology of the Gatori will allow mankind to survive global warming, multiply our lifespan by a factor of twenty, and cross galaxies at FTL speed. Please don't back away from this fight. NASA is big and NASA is brutal and I can't fight them alone. I need your help. Mankind needs your help. We stand on the brink of a reality more incredible than anything we've ever imagined. Go to my website soon and make it happen. Link and Paypal information to follow.
posted by Karmadillo at 6:48 AM on September 29, 2012 [5 favorites]


Percival Lowell is VERY pleased.
posted by pentagoet at 6:52 AM on September 29, 2012 [2 favorites]


So when are we going to get the manned mission to Mars to dangle the string?
posted by Ickster at 6:52 AM on September 29, 2012


At this point, we've had dozens of "proofs" that water existed there. Each one has an alternative explanation. But isn't the simplest overarching theory that water existed there?

Because that is how science works. You have to go very far down a road of evidence before calling a hypothesis "good."
posted by Danf at 7:48 AM on September 29, 2012


Its like discovering I used to have orange juice in my fridge , okay now what ?

You used to have orange juice in your fridge, but don't now. I currently have orange juice in my fridge. Am I in danger of ending up like you? How can I avert it? Is there a way to tell what other fridges might have orange juice without opening the door to see? Where did the orange juice come from? What other foods and drinks tend to accompany orange juice in fridges?
posted by DU at 7:54 AM on September 29, 2012 [27 favorites]


I love NASA and Mars and Water and stories about Mars but discovering something that is not there anymore seems more like history than science to me at some point.

Where we are right now (Cortez, Co), we are literally surrounded by evidence of stuff that isn't here anymore - people, flowing water, volcanic eruptions, geologic uplift, etc. How is studying that magically history and not science? It can be both.

I'm open to the idea that flowing water was not present on Mars. Are there decent alternate hypotheses for what caused the formations Curiosity and other rovers have seen?
posted by rtha at 8:07 AM on September 29, 2012


I WANT TO BELIEVE
posted by Renoroc at 8:14 AM on September 29, 2012


You used to have orange juice in your fridge, but don't now. I currently have orange juice in my fridge. Am I in danger of ending up like you? How can I avert it? Is there a way to tell what other fridges might have orange juice without opening the door to see? Where did the orange juice come from? What other foods and drinks tend to accompany orange juice in fridges?

DU, all of us came here tonight because we love you and we are concerned about you. What we have to say might be painful, but you need to hear it. I think it's time for you to re-examine your relationship with orange juice.
posted by Slarty Bartfast at 8:25 AM on September 29, 2012 [7 favorites]


This is one of the reasons I love the robotic exploration path that NASA has taken. Curiosity is able to, very slowly and deliberately, do science. Meticulously, thoroughly, carefully, it's exploring a small part of the Martian surface in minute detail.

And back here on Earth, we get to look at the results, and debate their significance. We're not caught up in the drama of having human beings in peril millions of miles away. The rover isn't planting flags, or doing scenes from The Amazing Race, or doing all of the thousands of things that are necessary for human survival.

If we'd sent human beings to Mars, and they'd spent days examining the soil meticulously, the planet would be outraged. Why aren't they leaping about in the low gravity; why aren't they EXPLORING, dammit?

The rovers get left alone to do the work. And we get to see what science looks like in a remarkably pure form.
posted by MrVisible at 8:29 AM on September 29, 2012 [5 favorites]


Seymour Zamboni: "Breccias have angular fragments. The observed rock layer doesn't look like a talus breccia to me. But then again the distinction between angular and rounded rock fragments is highly subjective at some point."

1. True
2. Agreed
3. Not really. It's a pretty big leap (and time, and energy for that matter) to make an angular rock fragment rounded (even sub-rounded in this case).

This is absolutely huge concrete evidence of mechanical weathering indicative of a moderate energy liquid environment occurring for an extended period of time at this location. Every sedimentology text you could find would back this up.

The more interesting question to me (and I expect many others) now is how long ago did the journey for this little clast end? Assuming it's at the top of the section (can Curiosity take strikes and dips? must look into that....) that means pretty recently in Mars history, given that the lack of tectonic activity seen on the scale of earth does not exist there. The rock cycle was probably completely stalled at some point.

Or the clast is 2/3billion years old and has been reworked. My mind reels. The presence of that clast answers definitively some questions, while raising a whole mess of others.

I've been following the Mars missions for years. I got downright emotional when I saw the picture of that clast.
posted by Big_B at 8:44 AM on September 29, 2012 [2 favorites]


Yes.

Oh, Grumpycat. He's not angry with you, he's just disappointed.
posted by Pope Guilty at 8:46 AM on September 29, 2012


I love NASA and Mars and Water and stories about Mars but discovering something that is not there anymore seems more like history than science to me at some point.

Geology isn't science?
posted by brundlefly at 8:54 AM on September 29, 2012 [5 favorites]


Big_B: There are plenty of examples of wind erosion causing rounding on Earth. It is difficult to argue that those clasts are significantly more rounded than what you see scattered around the surface of Mars, nor are they particularly as obviously rounded as the conglomerate in the picture (I would call them sub-angular myself, but as previously noted, this is highly subjective).

We know, as talitha_kumi says, that weathering and surface alteration are occurring NOW on Mars, and while we'd like to draw parallels to Earth, there are still things we clearly don't understand well about the chemical and mechanical weathering processes on Mars, and we're talking about some serious deep time here.

My point is not that they're wrong, they very well could be right, but good science comes through peer review and setting up and knocking down alternative hypotheses, not showing pictures on the internet and arguing from a position of authority. They may have convinced you, but, as a sedimentologist, they have a lot further to go to convince me. Convincing evidence could come very quickly as this mission progresses, and I am very excited to see what they uncover, but this is marketing, not science.
posted by grajohnt at 9:20 AM on September 29, 2012 [1 favorite]


I love NASA and Mars and Water and stories about Mars but discovering something that is not there anymore seems more like history than science to me at some point.

I, personally, would be ecstatic for a history of Mars.
posted by meese at 9:36 AM on September 29, 2012 [1 favorite]


We went to a brief presentation given by a "blue shirt" last weekend. During Q&A, someone stood up and straight up asked if lasers were real. I almost lost my shit.
posted by Brocktoon at 10:04 AM on September 29, 2012 [4 favorites]


I've always wondered....when they say "water" do they mean actual water, H2O? Or do they mean liquid? Is it possible that some ghastly chemical in liquid form could have flowed over the surface of Mars and had the same effect? Is this just wishful thinking? Are they so desperate to find actual water on another planet that they're overlooking a past Colorado River of ammonia or something that carved canyons?

In my experience, when planetary geologists say 'water', they generally mean an aqueous fluid - "liquid with H2O in it". According to Ms. Zamboni, a fluid with a pH of -2 to 14, or a brine so salty that it can't freeze, could all count as Martian "water" as long as it's got H2O in it.

can Curiosity take strikes and dips? must look into that....

Yes, using stereo data from the twin Navigation Cameras. "Left-eye" and "right-eye" images can be combined (in an analogous manner to the way your brain combines information from your eyes ) to get 3D information about rocks. Scientists on the Curiosity team can use this to quantitatively determine strikes and dips.

this is marketing, not science.

Sure, there's nothing definitive, but you can't hold a press release to the standard of a peer reviewed article. A couple of things to consider, though: On Mars, most float rocks are impact ejecta - stuff tossed out by meteorite collisions. This means they start off very angular. Additionally, these ones are at the base of a fan-based deposit which from orbital scale geomorphic context is believed to be an alluvial fan.
posted by zamboni at 10:05 AM on September 29, 2012


" . . . terminated a feline lifeform. Is that right?"


Yes. and No.


collapse of the quantum wave function in . . . 3 . . . 2 . . . 1 . . .
posted by exlotuseater at 10:07 AM on September 29, 2012 [1 favorite]


So when are we going to get the manned mission to Mars to dangle the string?

At the point where due to the level of radiation on the way there combined with the gravity well at the bottom it is accepted as a 1 way trip*.

*given what humans have for power generation for gravity well escape along with a lack of resources on the mars end.
posted by rough ashlar at 10:21 AM on September 29, 2012


News Flash: Curiosity just uncovered a seed.

It appears to be from an orange.
posted by mule98J at 10:43 AM on September 29, 2012


If there was life on Mars, that may explain this:

'UFO' found on Google Street View
posted by XMLicious at 10:52 AM on September 29, 2012


So are we back to the theory of canals yet?
posted by BlueHorse at 11:21 AM on September 29, 2012


Oops, I missed placed the focus there.
I was more picking on the headline of "Is there water on Mars !?! Yes! No! " which I have heard over enough that it feels like a oversimplification of the whole endeavor. But not too much .
I wasn't meaning to knock science or history, without them I'd be nowhere.
posted by epjr at 1:08 PM on September 29, 2012


I dislike reducing / limiting science to the presence or absence of peer review. Peer review is an essential tool in science, but its presence does not guarantee good science, and its absence does not automatically disqualify something as science.

Pure observation can be science too, and we are, through the eyes of a robot, observing the heck out of some rounded rocks on Mars. Which makes it awesome science.
posted by feckless at 2:02 PM on September 29, 2012 [3 favorites]


Unfortunately if it finds an entrance to the immense cavern with the ancient alien lever that will return the water and atmosphere the line of sight will be cut off and the scientists will not be able to control it.


No, the real problem is that, of all the different gadgets NASA put on Curiosity's robot arm, none is shaped enough like a four-digit hand to trigger the switch that releases the oxygen-rich atmosphere.
posted by straight at 3:56 PM on September 29, 2012 [3 favorites]


Hip-deep water, yes, but
posted by stargell at 4:01 PM on September 29, 2012


Whose hips?
posted by stargell at 4:01 PM on September 29, 2012


Mmmmmmm.... hips.
posted by butterstick at 4:08 PM on September 29, 2012


Humph. Just looks like some old concrete from a parking lot to me.
posted by drhydro at 4:41 PM on September 29, 2012


I overheard that Curiosity also found and terminated a feline lifeform. Is that right?

Indeed.

.
posted by homunculus at 12:31 AM on September 30, 2012 [1 favorite]


Whose hips?

Um...
posted by Skygazer at 1:59 AM on September 30, 2012


Some more really exciting news from Curiosity:

Turns out Mars is a lot warmer than we thought, too. Temps have reached above freezing roughly half the days since Curiosity started tracking temperature--and this is during what's considered to be late winter in the region of Mars where the rover's been measuring.
posted by saulgoodman at 7:13 AM on October 1, 2012


The temps have been measured at as much as 43 degrees Fahrenheit; that'd be considered fairly comfortable winter weather here on Earth.
posted by saulgoodman at 7:15 AM on October 1, 2012 [1 favorite]


Admittedly the lack of of oxygen would put a damper on things.
posted by Brandon Blatcher at 7:52 AM on October 1, 2012


blahblahblahscienceblahblach CONCRETE SLAB blahblahsmartpersontalkingblahblah MARS

Obviously, these are the remains of the once-great cities of Martian civilization.
posted by snottydick at 8:05 AM on October 1, 2012


But there's lots of oxygen on Mars, Brandon Blatcher.

It's just breathable atmospheric oxygen that's hard to come by.

I'm totally just spit-balling and/or speculating wildly here, but suppose something adapted to "breathing" iron oxide (of which there's plenty on Mars) in a way sort of crudely analogous to how fish on earth have adapted to extracting oxygen from water (despite the ocean's lack of atmospheric oxygen). In any case, I suspect the real story of life on Mars would be mostly subsurface most of the time (if we ever discover a story there at all).
posted by saulgoodman at 12:50 PM on October 1, 2012


(To be fair, fish breathe by extracting atmospheric oxygen from oxygenated water, not by some kind of biological process of hydrolysis, but what's to say life couldn't evolve to extract oxygen from its environment in other, novel ways, is the point...)
posted by saulgoodman at 1:09 PM on October 1, 2012


(And now that I think about it, Algae actually does extract oxygen from water using hydrolysis, so the idea of an organism extracting non-atmospheric oxygen isn't even unprecedented, and if there's free water anywhere on Mars, that'd be opportunity for certain simple forms of life to crop up.)
posted by saulgoodman at 1:18 PM on October 1, 2012 [2 favorites]


It's interesting to try and imagine what a creature would look like that could perform ferrolysis, though.

I'm imagining something with an exo-skeleton insectizoid aspect to it...but that's probably cos of Aliens.
posted by Skygazer at 5:06 PM on October 1, 2012 [1 favorite]


But there's lots of oxygen on Mars, Brandon Blatcher.

Wikipedia says it's just .13% of Mars atmosphere vs 20% on Earth. You calling Wikipedia a liar?!
posted by Brandon Blatcher at 5:37 PM on October 1, 2012


He's talking about the oxygen in the iron oxide in the soil and rocks.
posted by XMLicious at 5:47 PM on October 1, 2012 [1 favorite]


Awesome, we were talking about atmosphere.
posted by Brandon Blatcher at 7:14 PM on October 1, 2012


That wasn't clear from your comment, BB. You just said "lack of oxygen" would put a damper on things, you didn't specify "lack of atmospheric oxygen." And I'm not sure atmospheric oxygen is necessarily what's required, since per the example of algae, some terrestrial lifeforms do make use of non-atmospheric oxygen. Didn't mean to be snippy or anything if that's how it came across, BTW... I'm just speculating because, well, damn! Life on Mars might be a game-changer in so many ways.
posted by saulgoodman at 6:33 AM on October 2, 2012


Agreed, it is interesting to speculate about life on Mars.
posted by Brandon Blatcher at 8:33 AM on October 2, 2012 [2 favorites]


Are Those Spidery Black Things On Mars Dangerous? (Maybe)
posted by homunculus at 11:14 AM on October 4, 2012


Uh oh, the Spiderman's Symbiote is on Mars!
posted by Brandon Blatcher at 11:48 AM on October 4, 2012


Welcome to Glenelg: twinned with Mars
posted by homunculus at 5:08 PM on October 5, 2012


Life on Mars? Scientists hope to find it by decoding Martian DNA
posted by homunculus at 3:46 PM on October 20, 2012


Is This the Spaceship That Will Take Us to Mars?
posted by homunculus at 11:52 AM on October 22, 2012


Could Mars Rover Curiosity Come Home?
posted by homunculus at 3:03 PM on October 25, 2012


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