While listening to the show, a question crossed my mind : OK we can see gullies 5-10 Swimming Pools big but DO smaller ones exist? I mean smaller than MGS resolution i.e. the one MRO could see...
If Mickael Malin dam theory is right this could provide smaller one to occur but I'm looking forward to MRO pictures of the 2 gullies presented tonight as well as all bright one that are probably quite recent if I understood correctly.

PS : a to Doug. When you interview Jim Bell, your line is still much better than Ames'

"Interesting"?



"INTERESTING?"



Are you a VULCAN volcanopele [corrected] ?!!!! Does cold, coppery green blood flow through those veins? Did your left eyebrow merely lift quizically when you saw those images when you peered into your science monitor??

Do you know how long many of us "Out here" have been waiting for these images and this news? What we have there is the strongest evidence yet for Mars being a potential habitat for life, nothing more, nothing less. And I know some sticks in the fresh martian mud will say that that's too optimistic, too simplistic and going over the top - I don't care!!!!! I want to go out and laugh at the sky now! Look at the pictures!! Something poured out down those crater walls for a while. Something... wonderful... Something that is calling to us, siren-like, "Come and look more closely... come... come..."

Imagine standing there, on the rim of that crater, and seeing a gully in flow...

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... imagine feeling the rumble beneath your boots as the water breaks through and starts to gush... imagine seeing the water steaming and boiling in the low atmospheric pressure, sliding and slavering down the crater wall's slopes, dying even as you watched it... imagine watching the gushing stop, and the last of the free water evaporate away, leaving behind a glistening snakeskin of freshly-exposed salts, covered with glinting frost, like someone has spilled molten glass from above... Doesn't that make you feel amazed?!

We thought we knew Mars but we don't. We were fooling ourselves all along. It has secrets still, locked away in its rocks, maybe even just a gloved hand's depth beneath its dusty surface. Imagine that, an evolved monkey's hand trailing through the dust of Mars, its fingers digging down, down... what would it find...?

I know this post might seem over the top but I'm sorry, I'm on a high right now and in no mood to be cold and scientific. There wasn't just water on Mars a billion, a million or a thousand years ago, there was water there a couple of years ago, flowing... and there probably is now, as I type this. The implications of that are enormous, simply enormous. We should be celebrating, not downplaying it.

Go on volcanopele, put a party hat on, I dare ya...

Stu...

Where did you find that image? It is absolutely, stunningly beautiful! Please, is it some kind of public image, or is it covered by copyright? I'd love to use it on one of my websites....

...John...

I'm not tuvas. I'm not a vulcan, either, I'm an Ionian, and red-hot, ultramafic lava flows through my veins... My reaction was that this news was interesting and that I wanted to see those features in HiRISE images. But, no, I didn't get all that excited. Maybe it is my outer planets bias, but flowing, boiling acidic water just isn't as exciting as huge lava flows on Io, the Earth-like geology of Titan, the geysers of Triton, or I dare say, the ocean on Europa.

EDIT: I forgot Enceladus' geysers, how silly of me

And through your basilar and carotid arteries, too

I can't get either the msss or nasa links to work (Are they awash with hits?) so I've still only seen one pair of pictures on a BBC TV news screen. Could somebody post just the pictures?

I'm not Stu (you'd better change to Stugully now ). I get the point volcanopele and I also love "your" places, but we'll go physicaly to Mars ONE full century before the places you're talking about...and THAT is exciting...

Apologies for the mistake, written in haste, I've corrected it.

I agree that all your other things are exciting (except maybe the geysers of Triton... not too fussed about them), but they're a looooong way away, and we have no chance of seeing them up close and personal, with wide, startled human eyes, in our lifetimes or even two lifetimes after that. It's not the water itself that's exciting to me it's what it represents - a dynamic, warm-and-wet-in-places Mars - and what it teases, that there could be life there, right now. That "flowing, boiling acidic" water might be thick with microbes all shouting "Wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee!!!!!!!!!!!!!!" as they fly through the air... admittedly mere seconds before dying a horrible death, but hey...

The future just shifted beneath our feet, settling into a new structure and pattern. Surely someone else felt it too?

(that pic, by the way, is one I've had on my computer for ages, can't even remember where I got it now, but I think it was from a space calendar a friend gave me... sorry I can't be of much more help...)

here's a link : http://www.jpl.nasa.gov/news/news.cfm?release=2006-145
And images
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Pics...

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I'm very excited with these new foundings, also on the new impact features.

A quick search for other light-toned areas associated with gullies turned up this image; there is such an area in the big crater near the middle of the image.

http://www.msss.com/moc_gallery/s05_s10/fu...10/S1001717.gif

The hunt is open..

Nico

English is not my native language. I mean the water is not flowing for long periods of time (like a river), but only for short periods (maybe hours), but again and again. AND it's been recent.

Analyst

I concur. It is interesting; it demonstrated the usefulness of extended missions (and launching long-lived hardware), demonstrated again the power of serendipity and a sharp pair of eyes (Edgett/Malin appear to be saying the first new crater was spotted visually in a wide-angle context image, ie without comparison to the previous image of the same area!) and adds a nice detail to the current state of knowledge about sub-surface fluids. It probably helps eliminate up a couple of alternative explanations for the gullies (and if not, HiRISE et al will do so.) (Tho' AFAIK CO2 ice is still a possibility?) But exciting? More so than, say, the MER EDL, or Opportunity's arriving at Victoria Crater? I confess I was mildly excited when I heard the first rumours of a major NASA announcement, but having seen the names listed (and read this thread), the actual news was pretty much as expected. Spotting new craters is MORE exciting, to me, and I think will be seen to be a more significant single discovery in 10 years' time.

Moreover, I heard someone from the Beagle team interviewed on Radio 4 ("PM"), and he made a point of saying "yes, I know we've had these same stories about "water on Mars!!" every couple of years for the last decade." He was just getting his retaliation in first - I predict comedians (funny and otherwise) will be pointing that out before Saturday morning.

However, liquid flowing down the gullies shouldn't be news to anyone who's been paying attention. The original paper revealing the gullies already made it clear that they were clearly relatively recent features, and it is not that surprising that one or two would trickle for a minute or two once or twice a decade.

I think the image, attractive though it is, looks more like the Three Gorges than Mars From what I remember of the original paper, if you were there on the surface when one of these things was active you'd see a small, narrow strip of dirty water running straight down the slope, subliming as it went; not bursting out under enormous pressure and spraying tens of feet out into the air... the gully would cut much more deeply into the crater wall if it were that violent. I also wonder about the concentration of any putative salts... if it were very high, would that affect the flow characteristics of the water?

Right, I'm off to find another roaring fire to drape my wet blanket over

sigh... okay... so this isn't brand new "news", we all suspected what was going on, and little voices in our heads have been saying "water carved" ever since the first gullies were spotted... and yes, that image is over-dramatised, a real gully"burst" wouldn't be anything like as violent... and no, this wasn't as heart-pumpingly exciting as Spirit's EDL or Oppy's triumphant, knackered roll up to the rim of Victoria.... but come ON people!!! WATER ON MARS!!!! I refuse to let anyone spoil this night for me, not after I've longed for this news for so long. Get your dirty wet blanket away from my fire! I'm going to spend the night sitting by it under the stars, watching the golden sparks rise into the air, imagining each one is Mars, complete with gullies of steaming, silver-scaled water...

Weird. To me, they are all equally as exciting (including the geysers on Enceladus). Whatever floats our boats, I guess

The solar system is wonderfully active, H20 plays a huge role everywhere, and we have a new foundation for this incredible revolution in planetary science.

Hats off to Mars Global Surveyor and team! What a history!

Is the HiRISE camera going to take images of these areas? Do people really need to ask that!? The whole array of MRO's tools will be used, no doubt.

I'm on your side Stugully! Come on Far Rimers, Far Dreamers, wake up, we need your help. Where are you Dan?
Sorry Near Blanketers I feel Water less letal than projectiles forming craters. I was there when they said "water is flowing on Mars today", I was listening, there's NO doubt : T-O-D-A-Y, they said. I'm gona have a (salty) bath right away and T-O-D-A-Y

There was never much question in *my* mind on that, nor probably in anyone's at this point

Fantastic images... hats off to MGS indeed.

Thanks, Stu and climber for the pictures direct, much appreciated as the links are still "server not found" for me. I was able to scan some of the news releases though. I believe someone in the know said that on the evidence the probability of recent aqueous flow is 'high but not very high'. From most of the news reports you would think the certainty had been demonstrated. The trick now will be to catch one of these things moving on the scale of seconds or minutes - the maximum time one can imagine aqueous liquid surviving on the surface.

Bah! Seen one komatiite, you seen them all. I've seen thousands.

Jon

That's weird. I'm not having any problems loading and re-loading the MSSS pages.

It should be noted that IF this is water (I want to see NIR spectra with a niiiiiice OH stretch absorption peak right at 1.5 microns before I totally discount liquid CO2) then the conditions are perfect for lyophilization of bacteria etc. in the water as it escapes the ice dam and vaporizes/freezes. This would be THEE ideal spot to collect samples for a return analysis.

I believe the links below won't go active until tomorrow, unless one has special access during the embargo. In any event, here are the references to the paper and a related news article in the same issue:

Present-Day Impact Cratering Rate and Contemporary Gully Activity on Mars
Michael C. Malin, Kenneth S. Edgett, Liliya V. Posiolova, Shawn M. McColley, and Eldar Z. Noe Dobrea
Science 314, 1573-1577 (2006)
Abstract
Full Text
Supporting Online Material

Richard Kerr's accompanying "News of the Week" article: "Mars Orbiter's Swan Song: The Red Planet Is A-Changin'"

*LOL*
Stu, I just loooooooove that refreshing, vivid pictorial writing style of yours

Jason, come on now, this has to rank there with liquid water being identified at Europa as one of the most exciting discoveries in the Solar System!

Liquid CO2? Is that even possible at Mars? Somehow I don't think so... But I could be wrong...

You pays your money, you takes your chances...

Most of us don't think so.

But I see you haven't visited the Wild, Wild World of Hoffmanland. In that case, you'll need directions.

Make sure you're seated during the tour, though

This amateur is still skeptical, is the only evidence of water in these gullies the relative albedo (light instead of dark like most other dust/sand deposits)? The most likely explaination seems to me to be dry avalanches.

It's always good to be skeptical, Anoolios. That is a hallmark of good science.

As for your question, have you seen this page? Note that Malin et al. don't rely just on albedo, though that is a key piece of evidence.

The rate is higher but it's not as high as you might think given the difference in densities at the surface. The martian atmosphere is extremely thin and at the surface is comparable to the Earth's at around 35KM but because of the lower martian gravity it's scale height is higher (~11km vs ~6km for earth) it is remarkably similar in density to the Earth's atmosphere once you get above 75km or so if I remember correctly. For the most part it filters out a similar amount of "stuff". By similar I'd guess we're talking about a similar order of magnitude here but I'd have to do some digging to get a number I'd be willing to defend.

The percentage that reaches the ground is higher for another reason that could well be as important - the average atmospheric impact speed at mars orbit is slightly slower (5-10km/sec slower) and so there is less energy to dissipate. For asteroidal debris this is quite significant as the impact speed can be as low as 7km/sec at mars (vs ~17km/sec typically for Earth) so only about 17% of the energy needs to be disipated. Cometary and retrograde impacts are a different animal and the difference at Mars for these (compared to earth) is 80% and 50% respectively.

The main reason there are more apparent craters on Mars is that the surface is (for the most part) really and truly ancient and erosion rates are many orders of magnitude slower than on earth.

Also, proximity to the asteroid belt and Jupiter.

Thanks for that clarification. It definitely helped me with an off-list discussion.

...John...

The reason this news IS really exciting is that for the first time we can think of sending instruments to examine material which recently interacted with liquid water on Mars. Previously it was looking like we would have to wait for a machine which could drill hundreds of meters beneath the surface. The big question now is was the water ancient ice, melted and released in one brief event or are there liquid aquifers which occasionally find their way to the surface?

You decide:

Liquid CO2 will not be possible in 'open air' with the Martian air as thin as it is, same as on Earth.
But nothing prevents liquid CO2 from being kept underground if it have a good nice aquifier or perhaps a lid of frozen water. Yes the pressure would be great, but this could also explain features like the ones we see here.

I personally think CO2 are a more likely explanation. This simply from looking at the martian temperature range. The surface are simply cold, and when we look underground it should be even colder in most places!
(This except any and still-not-found-despite-looking geotermal hotspots).
Colder conditions underground places the thermometer in the right range for frozen CO2, which happens at -78 °C.

Narrow cracks in the ground might become CO2 traps when the area chills down in the night. We also seen signs of karst topography in Meridiani, if that idea turns out to be correct there might even be larger caves where CO2 ice accumulate on the walls. When it melts at −57 °C there might not be space for it to expand and reach the gasous phase and so it rush towards the nearest opening - and so we have a gully.

So I am fairly in the same camp as deglr6328 on this one.

There are plausibility arguments against sequestration of liquid CO2 in the martian near-surface. For example, see Stewart and Nimmo [2002] (440 Kb PDF).

Thank you, and I took the time to speed read a part of that text you linked.

But you are absolutely right, I wrote about liquid CO2 in the first paragraph since that was what tuvas asked about.

But the following sentence lacks the word 'frozen' and should have read.
"I personally think frozen CO2 are a more likely explanation .......... at -78 °C."

(And for once I dont edit, since I got back to the subject so fast)

Finally I take the opportunity to link a text where the author points out that the gullies seems to appear on the slopes facing away from the sun. Something that again are one sign that we might not be seeing the activity of water here.

And then again another link to one text that also discuss the CO2 as one alternative explanation for the gullies. Liquid CO2, Not Water, Likely Created Martian Gullies

Thanks, Myran. And yes, I'm familiar with Nick Hoffman's views.

Ahem . . . but we have at least one if not many more examples . . . which proves that life in extemely acidic niches on earth is actually TEEMING with microbes.

Please see this article. If you need more, Steve . . . please let me know.

http://www.sfgate.com/cgi-bin/article.cgi?...MNGBCCCDD21.DTL

I hope that Steve Squires has at least noted recently that extremely acidic environments on earth are not barren of life but do support strong colonies of microorganisms. What this means on Mars should not preclude that life does not exist. To the contrary with regards to the recent images and future images to come:)

Emily now has a story online at TPS.

EDIT: As well as a blog entry.

Have you watched/listened to SS talk at the OU? In the Q'n'A, when asked about the prospects of life he mentions that although life can survive well on earth in extremely acidic environments it is not clear that it can come into being in one. On earth, the microorganisms formed in a more benign environment and *then* evolved into being able to tolerate the harsh conditions.

The warm little pond theory may well be proven false in the near future. It has only been a theory that has to my knowledge "not" been proven. This basic article shows some of the current dissent among "the experts" about the origin of life:

http://www.economist.com/science/displayst...tory_id=5518892

The last two paragraphs are noteworthy. Regardless, whether life started on Earth in an acidic/basic hydrothermal spring, at the bottom of an early ocean in a hydrothermal vent, from a meterorite - the panspermia theory, or in a "warm little pond". The fact is we don't know. And we still don't know that much about Mars to make generalizations about whether or not if there was water on Mars - it was too acidic to inhibit the start of life there.

This is really exciting. Oh, to have a rover there! Maybe MSL will manage to be in a gully-prone area to get an up close look at these things. Until we get a ground truth look at these flows, there will always be doubts on water vs. CO2 vs. dust. But it is really looking more and more like water, which is so much more than just plain interesting. Wow.

Quite right I'm sure, I'm no expert on this.

All I was really trying to point out is that Steve Squyres has commented recently on this issue as you "hoped" and that that was (I think, I haven't had the chance to watch it again) his take on the matter.

As I read the Economist article, the point at issue there is hot or cold, not acidic or basic.

SS's comment, as I remember it, centered on the acidic environment. He suggested that while primitive life could develop in a neutral environment and then evolve a way to maintain an internal neutral state in acidic surroundings, this was not likely to happen from scratch in an acidic environment.

BTW Jim, do you happen to have a transcription of SS's OU talk? All I have is the audio file and I'd like to be able to search for the passages in question. (Even this Q & A would help).

Steve

Is there anyone here who will help me drag this poor, misguided individual behind the barn, where he can be taught a little bit of inner planet respect?
There is so much we probably don't know about life's origins. I figure, if there is hope for water, there is hope for life...

It wasn't so long ago that we all would have been jumping up and down about the discovery of any observed, recent change on Mars. I agree that these locations need to be be monitored with our newest orbiting instruments for verification, but hey, this is exciting news being released to commemorate the memory of a ten year veteran who has been lost in battle.

Let us all bow our heads in respect for a fallen comrade in arms.

You know, what give me real hope is that, let say, 20 years ago, life on Earth and water on Mars were understood a way that as been totaly changed nowaday. There IS life in extreme on Earth, there IS water on Mars today. I'll not related these two facts, I understand there could even be some politics behind this, BUT I feel that we are moving in the direction of "possible" life on Mars NOW. This has the BIG advantage to shake the people that decide the direction of future Exploration programs and, yes, as tsfisher say, they'll may be direct MSL in a place where gullies will be reachable. In my opinion, this is good new because this is one of the goal of exploring Mars and who imagined 3 years ago, before Oppy proved that Meridianii once see water, before MGS found active gullies that we could be talking now of landing a rover in a "waterworld"?

A question!

What's a likely figure for the viscosity of this water? I don't think I've ever seen viscosity estimates produced for (transient) liquid water in a Mars environment. Is it high (because the water's cold) or low (because it's near-boiling)?



Andy

What triggers my imagination in this great discovery is not the gullies...
Is the place where they we're originated...
Beneath...What can hide beneath?

I'll just join the choir...What great days we are living!