Tag Archives: Mars

EXCLUSIVE: Transcript of NASA News Conference Announcing Discovery of ‘Habitable Environment’ on Mars

We present here a transcript of the science presentations delivered  at a March 12, 2013 press conference  at which NASA Mars Science Laboratory (“Curiosity”) scientists announced that they had discovered evidence of what had been – how long ago may not yet be precisely determined –  a “habitable environment” on Mars.

The discovery – which is NOT the discovery of “life on Mars” – is another step forward towards that goal.  Having now found multiple proofs that water both flowed and pooled on Mars for long enough periods of time to have produced mineral-rich clays of a type very similar to those on Earth (in which, some scientists speculate, early multicellular life forms may have evolved on Earth), the NASA team will now search to confirm some of the most intriguing discoveries recently made, which their Principal Investigator team describes below.  These developments have come quite rapidly from this mission; we expect that there will be many more exciting discoveries made by the Curiosity team in the very near future – and as soon as they occur, we will try to bring the news to you.

As always, this transcript was produced by ourselves from the video on NASA’s USTREAM channel.  It’s still a nearly complete, uncorrected partial transcript; we were not able to complete Dr. Grotzinger’s “wrap up” of the press conference, though we do have the entirety of all the four main science presentations made, including the accompanying graphics.  We also have to go back and research the names of several scientists mentioned during the press conference, whose names we render here phonetically.  We also have not yet been able to listen to or transcribe the highlights of the “question-and-answer” session which took place at the end of these presentations, which you can see by watching the video.  We’ll try to get to that in the next couple of days.  Someday, the working class of the US will see the value in having a political party of their own and will be willing to properly fund such a party, at which time we will be able to do this work full-time for the benefit of the working class.  Until that glorious day dawns upon these United States, we have to continue to work other – far less important – jobs for a living!  All errors of transcription are our own.

IWPCHI

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[NASA Briefing on Curiosity’s Analysis of Mars Rock – 12 March, 2013.  NASA Headquarters, Washington, D.C.]

Moderator: Dwayne Brown, NASA Office of Communications

Dr. John Grunsfeld, Associate Administrator, NASA’s Science Mission Directorate

Dr. Michael Meyer: Lead Scientist, Mars Exploration Program, NASA Headquarters, Washington, DC.

Dr. John Grotzinger: Curiosity Project Scientist, California Institute of Technology (Caltech), Pasadena, California

Dr. David Blake: Principal Investigator, Curiosity’s Chemistry/Mineralogy Instrument (CheMin), NASA’s Ames Research Center, Moffett Field, California

Dr. Paul Mahaffy: Principal Investigator, Curiosity’s “Sample Analysis at Mars” (SAM) Instruments, Goddard Space Flight Center, Greenbelt, Maryland

Dr. Meyer:  “The NASA Mars Exploration Program has progressively approached the red planet from a global perspective to focus exploration of regions, past and present, that exhibit the potential for life.  Every successive mission has boosted our expectations that Mars could have been a ‘habitable planet’: a place that could have supported life.  This program of orbiters and landers have brought us to the point of seeking a habitable environment on Mars.  This is what brought the rover ‘Curiosity’ to Gale Crater.  Mineralogical, and geomorphological evidence from orbit showing that the area had significant amount of water in its’ past.

“As John mentioned, on August 6th, Curiosity landed spectacularly where we wanted in Gale Crater.  Within two months the team found an ancient riverbed: evidence of flowing water.  And we followed that downhill to ‘Yellowknife Bay’.  At the same time, we exercised the rover’s capabilities, tested the instruments for the first time, and doing science along the way.   We have now completed all the ‘first-time’ activities including the first sample drilled on another planet.

“This mission has been a fantastic team effort of engineers and scientists to deliver a highly capable exploration rover to Mars.  The rover is now fully commissioned for science; all the instruments are working; and the ‘keys to the rover’ have been turned over to the science team.  Woo hoo! [sic – lol]  [laughter]

“So, Mars has written the autobiography – its autobiography – in the rocks of Gale Crater; and we have just started deciphering that story.

“So, ‘Chapter One: Yellowknife Bay’:  This was an ancient environment with the right elements (minerals indicating a near-neutral environment) and slightly salty liquid water – all the prerequisites to support life; a habitable environment.  And so for the rest of the story, I’ll turn this over to John.”

Dr. Grotzinger: “Good.  Thanks, Michael. It’s a great science story, as Michael was saying; and I need to start first with acknowledging our colleagues that came before us, and also the entire planetary community that supported this mission.  As you know, developing MSL [Mars Science Laboratory – ed.] was a tremendous challenge and we had plenty of adventures there, but we got the support from our community and we really appreciate that.

I’d also like to thank the ‘Mars community’ and through the leadership of [Mack Donaldbeck?] and John Grant which led to the final selection of landing sites that ulimately led us to Gale, where we have had a terrific time so far – that’s been great.  And also, in particular, the MER mission; ‘Spirit’ and ‘Opportunity’; ‘Mars Express’ and also ‘Mars Reconnaissance Orbiter’.  ‘If we have looked farther it’s because we have stood on the shoulders of giants.’  And those missions allowed us to fine-tune our exploration campaign that led us to this place.

Finally, those of us that get to sit up here today are joined by our colleagues back at JPL [Jet Propulsion Laboratory – ed.] and elsewhere – the other P.I.’s [Principal Investigators – ed.] of the mission, including Ken [Edgett?], Ralph [Gellaert?], Don [Hassler?], Mike Malin, Igor [Mitrofanoff?] and Roger [Wiens?] and Javier [Gomelsavira?].  Every one of the instruments has led into the discovery that we have made here.  Some of those instruments presented back in January when we first talked about the geology and that ChemCam discovered the first evidence for sulfates in this area here.  You’ll hear more results coming out next week at LPSC [?] and then at EGU [European Geophysical Union?] over in Europe, in April, you’ll get to hear more still.

So this has been a very comprehensive exercise and we didn’t just stumble into this area; this is something that took a lot of planning.

O.K.  So let me go to the first display item and bring you back to where we were the night of landing, when we as a community first looked at this slide.

Image Credit: NASA/JPL-Caltech/ASU
Location of John Klein Drill Site

“We had selected as landing site; and the landing ellipse in particular was close to Mt. Sharp, which was considered to be our primary objective.  And so you can think about drilling an oil well here: you don’t just go in with one objective; you need primary objectives and you want secondary objectives.  And we had a secondary objective which was a distal part of this alluvial fan that you see here in the landing ellipse.  And we needed this in the back pocket in order to have the landing site confirmed by the review board, and then eventually accepted by headquarters.  And in case something happened to the rover we needed to make sure we had science to do in that landing ellipse.

“But that was sort of a… you can think of it as a back-up or a secondary objective and it turns out now, in fact, that it had become our primary objective at this point.

“We landed at the… there where it says ‘Curiosity Landing Site’ and we drove just a few hundred meters in the opposite direction.  We did this deliberately.  And this was based on the mapping that the science team did in advance of landing, and based on the previous mapping that came from ‘Odyssey’ and ‘MRO’ and all those great missions before us.  And in this particular case it led to the deliberate discovery.  So it wasn’t ‘serendipity’ or ‘luck’ that got us here; it was the result of planning.

“Now, what Paul and Dave will tell you about is the part that we do consider serendipitous: we had no idea that we were gonna go into the aqueous environment that we were predicting to exist here and also find sulfates and also find clays – and those guys will tell you about it.

“So that’s one of the reasons that we’re gonna be spending some time here.  So let me turn it over to Dave and he can tell you about ChemMin.”

Dr. Blake:  “Well thanks, John.  And, uh, you know, we got really excited when we first saw these uh… bedrock at ‘John Klein’ and saw these concretions and the reason is concretions are evidence of a water-soaked sediment – a soft sediment.  But what kind of an environment was it?  Was it ever habitable for life and if it was, would it preserve the organics for literally billions of years until we came here to take a look, to see if we could see what was there?

If you turn to the first graphic, you can see what made us think we really found something special.

Image Credit: NASA/JPL-Caltech/MSSS
First Curiosity Drilling Sample in the Scoop

“O.K.: well, this is what we call ‘paydirt’.  This powder in the scoop here is from ‘John Klein’ – the drill powder – and it’s gray-green, meaning that it wasn’t highly oxidized.  And you can see in the back of the scoop there, there’s a little bit of reddish material – this is from the ‘Rocknest’ – and this is highly oxidized.  So anyway what it shows you is that this material was never highly oxidized and therefore if there was organic material present there, it could have been preserved.

The second graphic shows a comparison of the two x-ray diffraction patterns that ChemMin has collected so far.

Image Credit: NASA/JPL-Caltech/Ames
Minerals at ‘Rocknest’ and ‘John Klein’

“On the left is ‘Rocknest’ soil; and on the right is the pattern we got recently from ‘John Klein’.  You can see they look very similar; and from our analyses we can tell you they both have igneous minerals – feldspar, pyroxine, olivine and magnetite.  What’s different: if you look at the ‘John Klein’ diffraction pattern – down close to the central point there – the intensity is due to clay minerals.  And you see they are labeled ‘Phyllosilicates’.  And we can tell you from our analysis there’s between twenty and thirty percent of a phyllosilicate called ‘smectite’; and that smectite forms in the presence of water – we know that.

In addition, we have evidence of salts like halite and calcium sulfates rather than iron or magnesium sulfates that were found at Meridiani [Crater – ed.].  And this suggests that the water was a relatively neutral pH and, in other words, it was a potential habitable environment.

So all of this is what mineralogy can tell you from an ancient surface that’s billions of years old.

So the next graphic shows you what we think a good terrestrial analogue is for this material we found in ‘Yellowknife Bay’:

Image Credit: NASA/JPL-Caltech/Ames
An Earth Analog to Mars’ Yellowknife Bay

The left image shows a clay-bearing sediment deposited in a lake bed in southern Australia; and on the right you see a core of this sediment.  And the different layers in the core represent different changes in mineral composition as the lake sediment was deposited.  And with that, I’ll let Paul talk about what the SAM instrument found.”

Dr. Mahaffy: “Thanks, Dave.  Just delighted to show you some results from SAM.  And I’m gonna explain a little bit about how we did this fairly complex experiment; but I thought it would be fun to bring along what’s a full-sized scale model of SAM – the ‘Sample Analysis at Mars’ experiment.

SAM and ChemMin are both very deep inside of Curiosity, so in these kind of beautiful ‘self-portraits’ that Ken [Enge’s?] camera takes of Curiosity, you don’t see much of SAM and ChemMin.  We have a test bed up at Goddard; you don’t see much of it either because it’s in an environmental chamber – it’s buried deep inside an environment that represents Mars.  So here [gestures towards model of SAM sitting to his left on conference table – ed.] we’ve kind of taken away the aluminum paneling and put on plexiglass and made a model.  And where the experiment starts that I’m gonna describe, we have just a little bit of sample located inside a SAM cup.  And I went last night into Amy [McAdams’?] lab up at Goddard and dug around and found some nontronite, which is a clay mineral of the type that we’re gonna be talking about today.  And I – there was a scale in there and I weighed out forty-five thousandths of a gram of that stuff because that’s about the amount that was in our SAM cup when we analyzed it.

So that’s where the story of this analysis that I’m gonna tell you starts; [begins demonstration, approximately 14:28 in the video – ed.] we have the sample in the cup in SAM – we have loaded it the previous ‘Sol’ (the previous day) – and we’re ready to do our analysis.

So, it’s night on Mars – the rover’s ‘gone to sleep’.  SAM’s kind of a night owl – we like to operate at night and – nobody else there to bother us – but’s it’s also a good thermal environment for some of the intstruments to operate.

And so, we had put the sample in the cup, through this little inlet tube – this vibrates as the sample’s going into the cup.  And then the sample manipulation system developed by our collaborators at Honeybee Robotics is, uh… can be seen down here.  And it turns out that the way the sample gets to the oven is: this little carousel rotates; the sample is dropped into the cup; the oven… the [corret?] cup moves over; and then it raises into
the oven – a very small oven where we take the sample up to the maximum temperature that I’ll show you.

And what we do then is that we start heating up the oven; we get a flow of helium going over the sample; we heat up the oven and then with the mass spectrometer (which is right in this area) we sniff a little bit of that gas and we measure the chemical constituents that come off.  And as we do that we  capture a little bit of gas in our tuneable laser spectrometer that was developed by Chris Webster’s team out at JPL; and we capture a little bit more of the gas in a ‘hydrocarbon trap’ because one of our objectives of this experiment really is to search for organic compounds on Mars.  And we, later, will send this gas to the gas chromatograph… I think I have a button here that will make one of the columns light up… and then the gas goes through those columns and the individual constituents come out one-by-one and then back into the mass spectrometer through a back door, and again we analyze what Mars is made of.

And so, if you go to the first graphic, we’ll show you some of the data.

Image Credit: NASA/JPL-Caltech/GSFC
Major Gases Released from Drilled Samples of the “John Klein” Rock

“And this really is just picking out the five major gases that were evolved from the sample.  And let’s start with what’s labeled ‘Water’ on top… but the mass that we’re monitoring – that is ‘mass 18’ (that’s the signature of water).  And you see the temperature scale on the bottom (going all the way up to fifteen hundred degrees Fahrenheit in this case).  And that water is coming off at really high temperature.  And that’s exactly characteristic of the smectite clays and it’s very good confirmation of what the ChemMin saw – we really do have clays here; and about thirty percent of the water that’s coming off is that… is that high-temperature water.

Go down to the lower left: you’ll see a blue trace; that’s oxygen.  We’ve blown it up by about a factor of ten in this case for illustration.  And we did see some oxygen at our ‘Rocknest’ dust pile; and we attribute that to the decomposition of a perchlorate, which is pretty interesting.  It looks like there’s very likely some perchlorate here as well.

The red peak is, likewise, carbon dioxide.  The carbon dioxide is produced either from oxygen reacting with carbon in the sample and making this carbon dioxide, or really the other alternative is the decomposition of carbonate.  And both of those possibilities are just fascinating, so that’s what  we’ll be pursuing as we progress with new samples and so on.

And then, finally, in the bottom right, at higher temperatures, you see masses labeled ’64’ and ’34’.  And those represent an oxidized and a reduced form of sulphur; they represent, respectively, sulphur dioxide and hydrogen sulphide.  And so, that’s just fascinating: we have both oxidized and – much more than in this atmospheric dust – much more reduced sulphur there as well.

What the tuneable laser spectrometer was doing in the meantime in this experiment was measuring the deuterium-to-hydrogen ratio in water.  And it… very interesting observation.  We had measured very high deuterium-to-hydrogen ratio in water evolved from the dust; and we understand that as being a signature of a good fraction of water having been lost from the Mars atmosphere over geological time.  And in this sample we see just the lowest deuterium-to-hydrogen ratio that we’ve seen in evolved gas so far; and  so that’s something that we’re gonna definitely be pursuing as we go forward with other samples.

So go to the next slide.  And here’s what the search for organics is looking like.

Image Credit: NASA/JPL-Caltech
Chlorinated Forms of Methane at “John Klein” Site

The data looks like… uh… signatures of mass-to-charge, just as I showed in the previous time; but here these compounds are coming out of the end of the gas chromatograph column.  And here we see two compounds that we actually had also detected at ‘Rocknest’: very simple chloromethane and dichloromethane compounds.  And it looks like they’re above the background level; it looks like they’re there.

Uh, we have to be very careful at this point in interpretation.  This was the very first sample that had gone through the Curiosity drill; and so there’s always the possibility that some residual carbon that was on the drill bit made its way into this sample.  So we’re really looking forward to repeating this experiment and seeing if these signatures of simple chloromethane compounds persist.

So, the really good news is the instrument is just working beautifully; it’s a credit to the very talented team that worked hard on not only making this stuff but making it robust and making it work in this very difficult environment on Mars.

So, with that I’ll turn it back to John for some additional comments.”

Dr. Grotzinger:  “Great. Thanks, Paul.  So, what I’d like to do now is sort of set the stage a little bit for what we view in this mission as the transition from the original goal, a decade ago, from the search for water on Mars to, now, the search for habitable environments on Mars.  And if we go to the first display item there…

Image Credit: NASA/JPL-Caltech/Cornell/MSSS
Two Different Aqueous Environments

“…what we can see are two rocks separated by a decade of research: the one on the left is from the ‘Opportunity’ rover back in 2004 (a rock called “Wotney”).  And what you see here is a rock – these images have been processed by Mike Malin and Jim Bell with what’s called ‘white balance’ – and it helps bring out our terrestrial intuition to sort of get a sense of what these rocks would look like if they were on Earth.  The one on the left is basically from the sequence of rocks at Meridiani Planum: a rock that is reasonably fine-grained; the particles were either formed in water or transported in water; it was then cemented in water (converted from sediment into rock); and then after that it was fractured and then some of the fractures were filled in with what looks like a relatively thin material (in this particular rock) but then you see all the bumps sticking out.  Those are the famous ‘blueberries’; these things we know are concretions.

“Well it turns out these things are turning up on Mars; and here on the right is our rock in the ‘Yellowknife Bay’ area called ‘Sheepbed’… uh, unit, we’ve named it.  And again you can see it approximately has the same color on the surface; it’s laced with these features that look like concretions to us; and the big difference is, is that you can see in that rock that it has a white veinfill running through it.  That’s the thing that ChemCam first hit; and told us that there were probably sulfates here.  So texturally, you see rocks that were transported in water, formed in water, cemented in water, altered in water and, uh… but that’s what you get on the surface.  And so what we need to do is scratch below the surface and if you go to the next one…

Image Credit: NASA/JPL-Caltech/Cornell/MSSS
Studying Habitability in Ancient Martian Environments

“…uh… this is what a decade of engineering gives you.  On the left, there’s a rock that was one of the first rocks that we ever interacted with at Meridiani with the RAT (Rock Abrasion Tool); and on the right we have the drill hole from Curiosity.  And the drill hole’s about one third of the size of  the RAT hole there on the left.

“But the big story is in the powder that’s generated.  And so, as we learned at Meridiani, we have a rock that is composed significantly of hematite in addition to the sulfates – iron-bearing sulfates – that indicate very acidic waters.   On the right, we get to see the ‘new Mars’: the gray Mars, that one that suggests habitability, that has these clays and other minerals present.

“So what, then, do we mean by habitability?  The key thing here is an environment that a microbe could have lived in – and maybe even prospered in.  So there’s three things that we want to point out today that Dave and Paul have shown you. And the first issue comes down to acidity. We don’t see any of the evidence that we have here – the rock on the left; the one from Meridiani?  It’s totally different in the subsurface in this rock on the right: we have the clay minerals (which form in neutral pH); we don’t see the iron sulfates (which indicate acid pH); instead we see calcium sulfate.  This rock, quite frankly, looks like a typical thing that we would get on Earth.  And it’s a neutral pH environment; and I think everybody has a sense of what ‘acidity’ means, but… there are some microbes that exist at very, very low pH’s… ‘but wait, there’s more!’

“And the second point is water activity: this is ‘how much available water there was for a microorganism to live in its environment?’  So with that, I’m gonna pull out a prop here [produces familiar plastic ‘Teddy Bear” container of honey – ed.]: it’s a jar of honey.  Everybody always wonders why it is that a solution of water and sugar can last on the shelf for ever and ever without spoiling.  And the reason why is that even though there’s a lot of water in this honey, there’s not enough that’s available for a microorganism.  And if a microorganism ends up in here, all the water will be sucked out of the cell – it’s this thing called ‘osmosis’ – and the organism won’t be able to live.

Turns out, the rock on the left there?  That’s what we think happened at Meridiani, but instead of sugar we had a salt called ‘magnesium sulfate’.  And there was so much of it that it would have inhibited microorganism[s] that lived there.  That was not a habitable environment.

And then there’s one more thing that we’re really excited about that we found at Meridiani – sorry; at Gale: and, uh… it’s a battery [holds up a typical dry cell battery – ed.].  And basically these minerals that Dave and Paul were telling you about – they’re effectively like batteries.  Some of them are negatively charged and they have various oxidation states; and what we have learned in the last twenty years of modern microbiology is that, very primitive organisms, they can derive energy just by feeding on rocks.  So when Paul talks about ‘sulfate versus sulfide’ and Dave talks about clays and magnetite, these are the kind of things that tell you that there could have been a flow of electrons in the environment, just like on this battery: you hook up the wires and it goes to the light bulb and the light bulb turns on… that’s kinda what a microorganism wouldv’e done in this environment if life had ever evolved on Mars and if it was present here.

So that’s what we mean by ‘habitability’: you take all three of those factors… and to really understand that, that’s what we built this payload for, and that’s what we feel that we have succeeded at.

[Question and answer session]

Q: “NBC in Los Angeles. Can you talk to me a little bit about the area where the rock was found? What would it have been like in ancient times? What would we have seen there?

A: [Dr. Grotzinger]:  OK… so, what we imagined it would have looked like was the picture that Dave showed [“An Earth Analog to Mars’ Yellowknife Bay”, above] we feel is a pretty good representation.  It’s conservative in the sense that it shows a lakebed that’s dry; the lakebed was filled by sediment that’s derived from streams… but we don’t know how long-lived it was; and so that’s always a challenge we’ve got on Mars.  It’s not like the rocks come with numbers on them that tell you how long the water was there, or how much there was there, ultimately.  But we believe that we wound up in this ‘Sheepbed’ unit at a place that was wet for a relatively long period of time – enough for all these chemical reactions to occur.

[…]

Q:  “Irene” from Reuters:  “Congratulations! This is pretty exciting stuff you guys are reporting today.  I have two questions: first is ‘What else needs to be done for analysis of the organics to… you mentioned a little bit about “the assessments were preliminary”; and the second question probably is for John: I know this is not a ‘life detection’ mission but given that you’ve scored a ‘hole-in-one’ so early, how much farther can you push this through the remaining eighteen months of the primary mission?”

[…]

A: [Dr. Grotzinger]:  I guess, Irene, the answer to the second half of the question is to underscore what you said, which is that we’re not a ‘life detection’ mission; if there was microbial metabolism going on, we really wouldn’t have the ability to measure that.  And if there were ancient microfossils in the rock, as good as MAHLI [Mars Hand Lens Imager – ed.] is… I mean it can tell us definitively that ‘we have a mudstone here’ but it would not be able to resolve individual fossil microbes.

What we can do is to survey additional targets that we have picked out; and we still want to go to Mt. Sharp and we hope to get there.  And there are different combinations of minerals that we see fron orbit that give us different prospects, and what I hope will become a burgeoning new field of ‘comparative planetary habitability’.  And what that means is that if you look at how we’ve studied the ancient Earth, and you look at the minerals and compounds and substances that are available, and you look at the ways that different prokaryotic microorganisms can do their metabolism… they use different materials; it’s almost like an organism has evolved to exploit every one of these little ‘rock batteries’ that exist in the record.  And so the question is: how many of these different kinds of ‘batteries’ can we find at Gale Crater?  And I think that really becomes our mission, along with the search for organic compounds.”

[…]

A: [Dr. Meyer (in response to follow-up question)]:  “[…] And as you mentioned, solar conjunction…we’re headed toward that.  Basically, we can’t talk to the rover and the rover talk to us for most of the month of April.  And so, what’s gonna happen is we’ll do some more science activities now – through the end of this month – permitting, with the engineers, confirming that things are safe for us to do those operations, but we will not do another drilling – the second drill hole – until after solar conjunction.  So that… we’re not gonna start that activity until May.”

Moderator: “Our next caller, from the Wall St. Journal, Robert Lee [Huntz?].

Q: ” […] So, gentlemen: in a simple, straightforward declarative sentence… or two, please tell my readers what you have found here and why it is significant.”

A: [general laughter] Dr. Grotzinger: “I can take a… I’ll take a swipe at that. I think we had a … we have found a habitable environment that is so benign and supportive of life that, probably, if this water was around and you had been on the planet, you would have been able to drink it.”

[Long pause – ed.]

Moderator: “I think that did it for him.”

[Laughter]

Moderator: “[…] let me take another question from Twitter: ‘The Opportunity rover: ‘three months’ and it’s going on for many, many years.  How long do you think Curiosity could last?’ ”

A: Dr. Meyer: “The half-life of its power is on the order of 84 years.  So I expect the rover to be there to shake the first astronaut’s hand… if the astronaut goes to Gale Crater.”  [laughter]

Moderator: “Next up: New York Times… Kenneth Chang. Ken?”

Q: “[…] I was wondering… given that [these rocks?] had good preservation, was there hope or expectation that they actually would have a stronger organic signal? And what does it mean that you don’t have a stronger signal?”

A: Dr. Mahaffy: […]

A: Dr. Grotzinger: “Kenneth, if I can I’ll just add a little bit to that. Paul’s reference to the early Earth is… you know in our history of exploration there… you have to have a search paradigm.  And that paradigm gets built on your understanding of the processes that result in the preservation of organics in the rock record.  And one of the big things on Earth is that because of plate techtonics we have a lot of heat that exists… that, of course, exists today.  So, a lot of organic compounds are degraded in the presence of that heat.

“On Mars, we actually think the planet cools with time, and so it may not be that heat’s the problem, it may be that radiation is the problem – something that we’re not so affected by on Earth.  So we have these three factors, as I said before.  To reiterate them (I think we’re all gonna have to learn these): the first is the primary concentration mechanism; the second is that all that ‘cool chemistry’ that creates the habitable environment – including the presence of water itself – is not necessarily a good thing for the preservation of organics.  And then the third thing is the radiation environment.  And so our ‘trick’ is to find a place where all three of those things ‘went right’ – and that could take the entire length of this mission… but we’re gonna give it our best.”

[…]

Q: Dr. Jim Green, Director, Planetary Systems Division SMD: “The one question I have, then: based on the observations, uh… what you’ve found out today is, would you say that Mars was habitable before or about the same time as Earth was in the history of the Solar System?”

A: [general chuckling on the panel] Dr. Grotzinger: “That’s a good question, Jim.” [laughter] “I’m not sure we’ll ever really be able to address that with our payload but, uh… you know, we’ve got a couple of different options here for the age of… of… just relative to Mars, how old these things are.  And right now, quite frankly, they go between being as ‘young’ as that alluvial fan lobe that comes down – which I think would be relatively young in the history of Mars – and it could be quite old.  Maybe these rocks are somehow related to the base of Mt. Sharp.  We can’t rule out that we’re looking at the base of Mt. Sharp right now – in a way?  So we’ve got a lot of options open before us… but I think, in any one of those versions, we’re talking about older than three billion years ago; and we’re probably looking at a situation where – plus or minus a couple hundred million years – it’s about the time that we start seeing the first record of life preserved on Earth.  It’s a great comparative planetary question.”

[…]

Q: Craig [Kovalt?] [Space Rep/ Curious Mars?]:  “The question on the clays: it’s one of the more significant findings is that you [had?] abundant water flow through the clay.  Uh… how does that relate to meteorite findings where they had also identified significant water [unintelligible] clays found in Martian meteorites? […]”

A: Dr. Blake: “Well, I think… you know, the clays in Martian meteorites were just… almost trace quantities and… probably… and the Martian meteorites that we’ve seen are mostly purely igneous rocks.  The clays in this rock – which is a mudstone (which was something deposited in a shallow aqueous environment) – are really a major percentage of the rock; and so they really represent a significant process.  Plus… I guess you could call meteorites the ultimate – what we call ‘float rock’: it came from someplace else and we don’t know where it came from.  We know where theis stuff came from: it came from this bedrock in Yellowknife Bay, and so we know that this environment existed in Yellowknife Bay with plenty of water.”

[To be Continued – IWPCHI]

NASA: Analysis of Mars Rock in Gale Crater Shows Life Could Have Existed on Mars

Yesterday,  in a news conference of scientists working on NASA’s Mars Science Laboratory (MSL) project, the announcement was made that the results of recent rock drilling operations on Mars have revealed that “ancient Mars could have supported living microbes.”

The results were reported by a team of scientists working with the MSL “Curiosity” rover, which has been exploring a region around Gale Crater on Mars where conclusive proof that flowing water was abundant in this location on the red planet was confirmed.   The scientists DID NOT state that they have discovered proof that life once existed on Mars, but that they have found proof that a water-rich environment in which pH levels that were consistent with what Earth-based life forms require in order to live were, indeed discovered.  ” ‘We have characterized a very ancient, but strangely new ‘gray Mars’ where conditions once were favorable for life,’ said John Grotzinger, Mars Science Laboratory project scientist at the California Institute of Technology in Pasadena, Calif.”

Scientists showed slides and photographs comparing two distinct water-rich environments discovered by NASA’s rovers in widely-separated locations on Mars: the location in Gale Crater where “Curiosity” is currently exploring, and the area where the earlier expeditions of the “Opportunity” and “Spirit” rovers discovered water-rich environments.

Although rock formations in both locations showed visually similar sedimentary rocks, the watery environment where “Opportunity” explored at Meridiani Planum in Endurance Crater was found to have contained water of a pH level too high to sustain life forms of an Earth-like nature.  “The Meridiani rocks record an ancient aqueous environment that likely was not habitable due the extremely high acidity of the water, the very limited chemical gradients that would have restricted energy available, and the extreme salinity that would have impeded microbial metabolism — if microrganisms had ever been present”.

Image Credit: NASA/JPL-Caltech/Cornell/MSSS 03.12.2013 Two Different Aqueous Environments This set of images compares rocks seen by NASA’s Opportunity rover and Curiosity rover at two different parts of Mars. On the left is ” Wopmay” rock, in Endurance Crater, Meridiani Planum, as studied by the Opportunity rover. On the right are the rocks of the “Sheepbed” unit in Yellowknife Bay, in Gale Crater, as seen by Curiosity. The rock on the left is formed from sulfate-rich sandstone. Scientists think the particles were in part formed and cemented in the presence of water. They also think the concretions (spherical bumps distributed across rock face) were formed in the presence of water. The Meridiani rocks record an ancient aqueous environment that likely was not habitable due the extremely high acidity of the water, the very limited chemical gradients that would have restricted energy available, and the extreme salinity that would have impeded microbial metabolism — if microrganisms had ever been present. In the Sheepbed image on the right, these very fine-grained sediments represent the record of an ancient habitable environment. The Sheepbed sediments were likely deposited under water. Scientists think the water cemented the sediments, and also formed the concretions. The rock was then fractured and filled with sulfate minerals when water flowed through subsurface fracture networks (white lines running through rock). Data from several instruments on Curiosity — the Alpha Particle X-ray Spectrometer, the Chemistry and Camera instrument, the Chemistry and Mineralogy instrument, the Mars Hand Lens Imager, the Mast Camera, and the Sample Analysis at Mars instrument — all support these interpretations. They indicate a habitable environment characterized by neutral pH, chemical gradients that would have created energy for microbes, and a distinctly low salinity, which would have helped metabolism if microorganisms had ever been present.

This is obviously very exciting news and brings us one step closer to the discovery of actual evidence of life on Mars.

Whether or not life ever existed on Mars is really not that important.  The fact is that it’s obvious that Mars, for whatever reason, could not support Earth-like life forms under the conditions which exist there today.  The environmental conditions we have discovered already on Mars, as well as on Earth’s other, uninhabitable planetary neighbor, Venus, prove just how fortunate we are to have the amazing planet Earth to live on, and how delicate is the balance between all the elements necessary for advanced life forms to exist on any planet “lucky” enough to orbit within a star’s “habitable zone”.

This is why we support the idea of abolishing the capitalist economic system and replacing it with an egalitarian socialist planned economic system.  The development of capitalism long ago reached the limits of its progressive character.  Placing the interests of a handful of competing entreprenurial billionaires above the interests of the billions of people living on this planet simply makes no sense at all.  These billionaires, organized as they are in competing nation-states, armed to the hilt with weapons of mass destruction endlessly fight over the limited natural resources available to us all.  Their struggles to pursue selfish ends have already produced two savage World Wars, and today threaten to plunge the world into a nuclear holocaust that could send human civilization, in the short term, back to pre-industrial levels of development – and destroy the delicate balance of Earth’s environment upon which all life forms on this planet depend.  For our civilization to allow a handful of greedheads to plunge this world into a death-spiral would be the greatest tragedy possible to imagine – and we have the power to prevent this from happening – but not if we allow human society to remain organized into competing capitalist nation-states.  That way lies World War Three.  As socialists we must warn our fellow human beings: you have a choice between socialism or barbarism.  Which will you choose?

If we as a civilization “decide” to stick with the greed system, we believe we will be “deciding” to wipe out life – or at least human life – on this planet.  That is unacceptable to us, and it should be unacceptable to you as well.

Workers of the World, Unite!

IWPCHI

[Sources:  NASA’s Mars Science Laboratory website“NASA Mars Rover News” on USTREAM TV]

First Fossils Discovered on Mars? NASA Mars Rover Finds Rocks With Strange Barnacle-like Protrusions

NASA’s Mars Curiosity rover has discovered a very interesting sedimentary rock formation in the “Yellowknife Bay” region of Gale Crate that contains blister-like bubbles that look very much like barnacles.   We have no idea what these rocks are or what these embedded bumps are, but if this was found on Earth in sedimentary rock, it would most likely be described as some type of fossil.  See for yourself.  Look at the rocks just above the steel frame of the Curiosity rover on the right of the image.  Very interesting find!  Can’t wait for the next briefing from the rover’s science team!  Could these be fossilized bubbles in the mud?  Or are these the first actual fossils discovered on Mars?

[Source:  http://mars.jpl.nasa.gov/msl-raw-images/msss/00152/mcam/0152ML0846000000E1_DXXX.jpg%5D

This image was taken by Mastcam: Left (MAST_LEFT) onboard NASA's Mars rover Curiosity on Sol 152 (2013-01-09 07:41:32 UTC) .  Image Credit: NASA/JPL-Caltech/Malin Space Science Systems

This image was taken by Mastcam: Left (MAST_LEFT) onboard NASA’s Mars rover Curiosity on Sol 152 (2013-01-09 07:41:32 UTC) . Image Credit: NASA/JPL-Caltech/Malin Space Science Systems

 

 

SPOILER ALERT! NASA Squashes Rumors of Impending Announcement of Major Discovery on Mars

The capitalist news media has been pushing rumors that NASA was about to hold a news conference announcing that a major discovery has recently been made on the Red Planet by the Mars Science Laboratory (a.k.a. “Curiosity”).

This rumor-mongering was started, inadvertently, by Dr. John Grotzinger of Caltech, who made some intriguing allusions to big news coming out of the MSL program just in time for X-mas during a NASA teleconference a few weeks ago.

Today, NASA published a press release downplaying the rumors, which were beginning to focus on an upcoming news conference to be presented by MSL scientists at the fall meeting of the American Geophysical Union, which will be held in San Francisco on December 3rd.

Today’s NASA press release stated baldly that “[r]umors and speculation that there are major new findings from the mission at this early stage are incorrect.  The news conference will be an update about first use of the rover’s full array of analytical instruments to investigate a drift of sandy soil. One class of substances Curiosity is checking for is organic compounds — carbon-containing chemicals that can be ingredients for life. At this point in the mission, the instruments on the rover have not detected any definitive evidence of Martian organics.”

Audio and visuals from the 3 December NASA/AGU press conference will be broadcast live on USTREAM.  The text of today’s no-fun bubble-bursting press release from the wet blanket brigade over at NASA is available here.

So tell everyone to put their tinfoil hats back into storage – “little green men” have not been discovered on Mars.  And the religious leaders of the world can breathe a big sigh of relief – for now.  Life has not been discovered on another planet, utterly destroying thousands of years of mythologizing “the uniqueness of God’s creation here on Earth”.

Yet.

IWPCHI

NASA’s “Curiosity” Rover Confirms: Water Once Flowed on Mars; Now “The search for habitable environments” Begins

Remnants of Ancient Streambed on Mars discovered by Mars Science Laboratory “Curiosity” rover. Photo credit: NASA/JPL-Caltech/MSSS

In the first of what we hope will be many blockbuster discoveries, the Mars Science Laboratory’s  “Curiosity” rover science team, after less than 2 months on the surface of Mars, has announced that they have discovered an outcrop of conglomerate rock that proves that water once flowed “vigorous[ly]” on the surface of the Red Planet.  They describe it as an “ancient streambed”.  Not only that, but at the end of the press conference, Dr. John Grotzinger, the Project Scientist for the Curiosity rover programme stated that “we have now discovered evidence for water, and what we’d like to do is to begin to characterize habitable environments” [our emphasis – IWPCHI] that might have existed on Mars while this water was flowing over what appears to the NASA team to have been an as yet unquantified but extended period of time – definitely more than just “thousands of years”!

In the press conference held today (Thursday, Sept. 27), a team of NASA scientists made the announcement.  Dr.  Grotzinger,  made the initial presentation:

“As we were driving along on the way to Glenelg, we encountered some really interesting outcrops that were surprising to the team.  And in the first graphic, [see photo above] what you’ll be able to see are these outcrops.  And this is one of them [shows PIA16156].  It’s named “Hottah”… and to us it just looked like somebody came along the surface of Mars with a jackhammer and lifted up a sidewalk, uh, that you might see in downtown L.A., uh, in sort of a construction site.  So you can see this rock unit; and it’s about 10-15 centimeters thick, so it’s sorta on that scale [holds up thumb and index fingers to indicate what 10-15 cm looks like], and it’s tilted: in the perspective you’re looking at it’s tilted off to the right; and what it does is it exposes the materials that, that make up this slab of rock.  And there’s a couple of these; and what we’re gonna be presenting today, my colleagues here will show you, what represents the consensus opinion of the science team: that this is a rock that was formed in the presence of water.  And we can characterize that water as being a “vigorous flow”, on the surface of Mars. And we, we’re really excited about this because this is one of the reasons that we were interested in coming to this landing site was because it presented from orbit quite a strong case that we would find evidence for water on the ground.  Turns out, that in fact we landed on this unit.  And this makes a great starting point for us to do more sophisticated studies using the rover payload.”[Source: USTREAM.TV,  “NASA Mars Rover News: Ancient River Streambed” Recorded live on September 27, 2012 12:46pm CST]

Over the past 6 years, the Mars Reconnaissance Orbiter has taken numerous spectacular high-resolution photos of Mars which showed what appeared to be unmistakeable evidence that liquid water once flowed – and possibly still today in some form flows, on Mars.  Features were spotted that showed what looked like traces of water seeping out of cliffs; stream and river beds were found, and many other geological features indicated that it was a near-certainty that water has flowed on Mars and may still be flowing.  Later, the 2 earlier martian rovers, “Spirit” and “Opportunity” also took photos and made observations of regions on Mars that contained rock formations and mineral forms that most likely were created in the presence of water.  Now, we have clear evidence that small grains of sand and larger pebbles and even what are described as “cobbles” contained in a slurry of what is similar to very coarse concrete were moved and brought together in a matrix in a form extremely common, seen on Earth in stream and river beds all over our planet.

When NASA scientists were looking for a landing site for “Curiosity”, they sought out locations to land that would place the rover within a short driving distance from these water features.  The selection of the apron of what appeared to be an alluvial fan at the foot of Mt. Sharp on Mars seemed well-suited for finding water features such as the one announced today.  But most surprisingly, Curiosity, it turns out, landed RIGHT ON TOP of an ancient stream bed!  The rockets that were used to gently land the rover on Mars blew away the surface dust from the top of the landing site, revealing the first stream bed outcrop practically under the rover!  To say that this is a wonderful surprise is a vast understatement.  It’s an extraordinarily lucky occurrence that just continues the incredible success of the MSL project so far.

Dr. Mike Malin of  Malin Space Science Systems, San Diego, the designers of the magnificent cameras on both the Mars Reconnaissance Orbiter and the “Curiosity” rover, made a presentation at today’s news conference as well, in which he compared rock outcroppings found here on Earth that were created by flowing water and compared them to the rock outcrops discovered by Curiosity.

“I’m going to show you how we had anticipated, with the design of the cameras, this type of outcrop; and how, when I briefed the media at the launch briefing for science on the 23rd of November, I actually used as an example, this would be the type of rock that the [mast] cameras would excel on.”

First, Dr. Malin showed a slide depicting a rock outcrop that is composed of conglomerate.  “This is a conglomerate bedrock outcrop in central Utah.  It’s about 100 million years old… and it’s really a rock made out of a bunch of pieces of gravel.  […] The white squares are enlarged at the bottom of this [image]… if you look at the [close-up] on the [lower] right, you can see there are a few bands of light-toned intermixed with a sort of speckly texture… the speckly texture is the conglomerate.  It has lots of little pebbles in it.  The lighter toned things are sandstone.  So there was sand moving down along a stream, along with cobbles [and] little pebbles…”

Images of rock outcrop just south of Green River, Utah, of ancient (Jurassic Period, around 150 Million years old) rocks exposed by erosion of a large amount of sedimentary rock in the area. Credit: NASA/JPL-Caltech/MSSS

Close-up of Green River, Utah rock formation showing areas of deposition of fine-grained sediment and areas of gravelly deposits. Image credit: NASA/JPL-Caltech/MSSS

Describing the photo above, which is an extreme close-up of the same Utah outcrop of conglomerate taken from 10 meters away, Dr. Malin said: “these are water-lain sediments that were then turned into a rock.  And then that rock has been eroded away, showing us this large outcrop.  The next slide shows a feature on Mars…

Curiosity rover photo showing the blast scour left by it’s descent stage’s rocket engines. This was one of the first photos taken by Curiosity of its landing site.
Credit: NASA/JPL-Caltech/MSSS

“…our first view of this similar type of rock came where the landing engines blew away the dirt and unveiled this layer beneath the surface debris; and you can see in the upper left corner of the enlargement of that white box that shows that there’s a layer there that seems to have rocks embedded in it.  We have a higher resolution view of that in the next slide, which was taken with the MASTCAM-100;

Close-up of blast scour from Curiosity’s descent engines which revealed conglomerate rock formation from ancient stream bed. Credit: NASA/JPL-Caltech/MSSS

“…and you can see, in the lower left now, that the gravelly surface and the gravel at the edge of this layer.  This is a relatively thin layer of this outcrop of the material that you’re gonna see in a few minutes.  But, basically, we had anticipated and discussed – both before the launch and right after landing – that where we were going should have these “water-lain” sediments that had been turned into rock.”

Next up was Rebecca Williams, Senior Scientist at the Planetary Science Institute:

View of ancient Martian stream bed, dubbed “Hottah” by NASA’s Mars Science Laboratory team. Image credit: NASA/JPL-Caltech

“…This is the “Hottah” exposure that John introduced you to… we were really just extremely fortunate to have such an ideal viewing geometry of this material.  This is a fractured rock outcrop that has been naturally tilted… we acquired these images on Sol 39 [the 39th Martian day that Curiosity has been on the surface of Mars]… and I’m going to zoom in on the lower left-hand  portion of this [image].

Close-up of “Hottah” outcrop, an ancient stream bed discovered by NASA’s “Curiosity” rover, showing varied size of materials in this layer of conglomerate. The circled portion is of a large pebble encased in the layer. Image credit: NASA/JPL-Caltech/MSSS

“…what you see is: this rock is made up of rounded gravels – there’s one circled for you at upper right – and a matrix that’s very sand-rich… these attributes are consistent with a common sedimentary rock type called a “conglomerate”.  Now, the clast that is circled is about 3 centimeters across… and you’ll see that the perimeter has a very rounded shape; it’s been worn by abrasion in a sediment transport process.  And you’ll also notice the gravels sticking out from the rock; and over time, erosion is working on that rock face and liberating some of the gravels, and they’re falling down and accumulating on a pile at the base of the outcrop.

A second exposure of this very same material we saw on Sol 26, and imaged it with the MASTCAM-100 (the narrow-angle) on Sol 27…

Second outcrop of ancient Martian streambed (dubbed “Link” by the science team working on NASA’a Mars Science Laboratory) shows clean exposed cross-section of the conglomerate layer indicating clearly that the small pebbles and larger rocks in the layer had been transported by “vigorously flowing” water. Image credit: NASA/JPL-Caltech/MSSS

“… and this outcrop’s name is “Link”.  You see the very similar textural properties that we saw at “Hottah”; again, very rounded gravels in a light-toned sandy matrix.  And, again, we have that gravel pile that’s adjacent to the rock outcrop.  So, by looking at the size and shape distribution of the gravels that are not only in the rock outcrop but those that we infer were liberated from the rock outcrop there on the surface, we can get a good idea of the range of gravel size and shape properties that you see there.

“On the next slide, we’ll zoom in…

This set of images compares the Link outcrop of rocks on Mars (left) with similar rocks seen on Earth (right). A typical Earth example of sedimentary conglomerate formed of gravel fragments in a stream is shown on the right. Rounded grains (of any size) occur by abrasion in sediment transport, by wind or water, when the grains bounce against each other. Gravel fragments are too large to be transported by wind. At this size, scientists know the rounding occurred in water transport in a stream. Image/caption credit: NASA/JPL-Caltech/MSSS and PSI

“…and there’s another one of these rounded gravels that’s about 1 centimeter across (that’s roughly the size of a plain M&M [Nice comparison! – IWPCHI]); and geologists are interested in rounded gravels because they tell you that those particles have been subjected to a sediment transport process, either by water or by wind.  And, so, typically, you start off with a very angular rock fragment, and as it’s transported it’s bouncing along, interacting with other grains and the surface, and that wears away the edges until you have a very smooth surface such as you see here in this pebble [she holds up a small, rounded stone taken from a streambed here on Earth].  And the key components of these gravels that we’re seeing here are: one, the rounded shape, but also the size [emphasis in voice – IWP].  These are too large to be transported by wind: the consensus of the science team is that these are water-transported gravels in a vigorous stream.

“On the right of the graphic, you can see a typical streambed deposit: it’s a gravel conglomerate that has gravels of the same size and roughly the same roundness as we see on Mars.  And so this is just wonderful “ground truth confirmation” of water-transported material that was predicted based on analysis of orbital images.” [!!! – IWPCHI]

The next scientist up to speak at this amazing news conference was Dr. William Dietrich, (Dept. of Earth and Planetary Science, University of California, Berkeley):

“So, I’m going to ask the question: ‘Where did these gravels come from, and what was the environment like at the time of deposition of the deposits that we now see at the rover site?’  And to do that, I’m going to use a term called ‘fan’, and, specifically ‘alluvial fan’; and to explain that, I’m going to take you on an aerial tour: first through Death Valley [desert in California, USA – IWP] and then back to Gale [Crater, where the “Curiosity” rover is situated -IWP], and connect the dots between the fan and  the deposits we see.  So,  if I could have the first video… [MPEG-4.  Additional videos are available here:  http://mars.jpl.nasa.gov/msl/multimedia/videoarchive/– IWP]

“… I introduce you to an area you’re familiar with: there’s Los Angeles, and there’s Las Vegas, I-15 [Interstate Highway 15 – IWP] in between.  And we’re going to take a flight just to the right of Zzyzx [desert town in California – IWP], and where there are six fans (outlined in white) that illustrate the form and process that I want to talk about. [Video starts and he narrates] So we’ll zoom in… and you’ll see the four [alluvial fans – IWP] that are facing us: the white lines delineating the lateral boundaries of sediment deposition that has occurred as a consequence of sediment and water rushing out of the canyons that are on the hills there.  And we’ll now go up to the headwaters… and we see the stream confine the canyon.  And then it reaches the front of the mountain; and as water and sediment rushes out, it spills.  And as it spills it forms a sheet of water or it runs out as discrete channels.  And you can see them there: shifting right, shifting left.  As it deposits, it elevates and shifts right, left, back and forth, building the fan structure that’s so characteristic and so identifiable.

“We rotated it across this white-toned fan; and now we’re settling down and looking back.  So now you see the fan shape, just like a fan that you would use to cool yourself off on a hot day.  You see the white outlines of the structure; and you see how it’s a result of water and sediment pouring out of the canyon.

“So if I could now go to the next video, [this “next video” is edited together with the first video in the link above – IWP] we’re going to go to Gale Crater [on Mars – IWP].  And we’re flying from north to south; and you see (in red lines) the lateral boundaries of a fan just like we saw in Death Valley.  And we’re looking down at a canyon:  a canyon that is about 11 miles [18 kilometers – IWP] long, 2000 feet [600 meters – IWP] wide and about 100 feet [30 meters – IWP] deep.  And that canyon was cut by stream flows.  And that stream and sediment then entered the crater rim wall and spilled out left and right; and the blue lines delineate distinct channels that we can recognize.  Fossil [stream – IWP] beds if you like.  We look at these channels and we see that they cut across the fan system.  And to us they suggest that this fan did not form in a single instance but this records some duration of a process.

“Now, we find… we settle down, and there’s “Curiosity”: it’s about a two to four-mile [3 – 6 kilometer – IWP] hike from the nearest channel to Curiosity – all downhill.  So we think it’s reasonable to suggest that the water and sediment came down that fan that we see now… [referring to video – IWP] […]  And, looking back [referring to the video’s aerial view showing the alluvial fan system on Mars – IWP], you see a watershed:  you see a canyon; you saw a fan; you see channels.

“Now: what was it like then, if you were standing at, exactly, Curiosity’s site at the time of the sediment deposition?  And the next video will show that. [Shows a video taken with an underwater camera in a fast-moving stream on Earth, which is part of this video here]   So, here is water moving sand and gravel.   It’s a  vigorous sediment transport process:  bursts and sweeps of turbulence mobilizing, together, sand and gravel.  And, of course, the consequence of that motion is collision, breakage and rounding of particles.  And in a flow that we can estimate for the rover site, that might have been from ankle- to hip-deep and maybe moving a few feet a second.

“And we arrive now…

This image shows a dry streambed on an alluvial fan in the Atacama Desert, Chile, revealing the typical patchy, heterogeneous mixture of grain sizes deposited together. On Mars, Curiosity has seen two rock outcrops close to its Bradbury Landing site that also record a mixture of sand and pebbles transported by water that were most likely deposited along an ancient streambed. Image/caption credit: NASA/JPL-Caltech/UC Berkeley

“… at what the bed of the rover site might have looked like after the last flow (of course, visited by a few Earthlings).  That was the Atacama Desert [in Chile – he refers to the photo above – IWP].  You see the heterogeneous bed; you see the patches of sediment.  And what we can think about, then, is that we were in a watershed.  We saw… going from an uplands to a lowlands.  And we would start with a rock [places large, heavy, angular piece of stone on desk in view of cameras – IWP] that would be big and broken, like this.  And it would travel something like 20 to 25 miles [32 to 40 kilometers] and end up something small and rounded like this [indicating much smaller rounded stone on desk – IWP].

Going from this [indicating large angular stone] to this [indicating small rounded stone] is direct visual evidence of the wear by what we call “bed-load transport”: of the wear, particle collision and the transport by water to the site of interest.”

Dr. Grotzinger wrapped up the news conference with some interesting information regarding the upcoming experiments that will be conducted by the Curiosity rover:

“First of all, this represents a great collaboration between the Curiosity rover and the orbiters that are routinely mapping Mars.  Now, in the case of looking at the alluvial fan, we see that that’s provided by both the  “HiRISE”  imager, the CTX imager  [one of the instruments on the  Mars Reconnaissance Orbiter] , previous generations of imagers…  [the imagers – IWP] look at these features that geologists have long thought of as alluvial fans.  But now that we’re down on the ground with Curiosity we can see the textural evidence that Becky and Mike talked about where you see the individual pebbles, the rounding, the geometric relationship that they have to each other that gives us a sense for that.  So if we just go back one, please…

This map shows the path on Mars of NASA’s Curiosity rover toward Glenelg, an area where three terrains of scientific interest converge. Arrows mark geological features encountered so far that led to the discovery of what appears to be an ancient Martian streambed. The first site, dubbed Goulburn, is an area where the thrusters from the rover’s descent stage blasted away a layer of loose material, exposing bedrock underneath. The second feature, a naturally exposed rock outcrop named Link, stood out to the science team for its embedded, rounded gravel pieces. The final feature, another naturally exposed rock outcrop named Hottah, offered the most compelling evidence yet of an ancient stream, as it contains abundant rounded pebbles. The grain sizes are also an important part of the evidence for water: the rounded pebbles, which are up to 1.6 inches (4 centimeters) in size, are too large to have been transported by wind. The image used for the map is from an observation of the landing site by the High Resolution Imaging Science Experiment (HiRISE) instrument on NASA’s Mars Reconnaissance Orbiter. Image/caption credit: NASA/JPL-Caltech/Univ. of Arizona

“… we should be able to see where these different features occur on our route to “Glenelg”.  And so, “Golburn” was the outcrop that Mike talked about, the one that we got for free way back when when the thrusters blew the soil away.  And at that time, the team came up with a number of hypotheses to potentially account for this.  And then we had a lot of discussion about it; and then we worked our way to “Link”, where we were able to see the first of the outcrops that Becky talked about,  and we began to wonder about the streamflow option as being the most likely candidate.  And it was really when we got to “Hottah” where we saw this again, most clearly, that it was very easy to reach team consensus to come to you and present the story about where we are.

“Now the rover is about 3/4 of the way between “Hottah” and “Glenelg”; and we’re working our way down into that key area where these three terrain types come together.  So if we can go to the next one…

This image shows the topography, with shading added, around the area where NASA’s Curiosity rover landed on Aug. 5 PDT (Aug. 6 EDT). Higher elevations are colored in red, with cooler colors indicating transitions downslope to lower elevations. The black oval indicates the targeted landing area for the rover known as the “landing ellipse,” and the cross shows where the rover actually landed. An alluvial fan, or fan-shaped deposit where debris spreads out downslope, has been highlighted in lighter colors for better viewing. Elevation data were obtained from stereo processing of images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. Image/caption Credit: NASA/JPL-Caltech/UofA

“… again, just to remind you, something that we showed you before we landed – in the press conference before then – we see the alluvial fan and “Peace Vallis” – which is now an official name that the IAU [International Astronomical Union – IWP] has approved as the entry point for water into this feature… what we were uncertain of at the time of landing was whether or not this alluvial fan extended all the way down into the landing ellipse.  And you see where we landed is quite a bit away from where you would identify – as Bill said, it’d be a few miles’ hike to get to the base of the alluvial fan.  So it looks like – at least intermittently – that that fan extended down to where the rover was.  That’s our most popular hypothesis right now for the team.

“The other part of the story that we talked about is in the last slide…

This false-color map shows the area within Gale Crater on Mars, where NASA’s Curiosity rover landed. It merges topographic data with thermal inertia data that record the ability of the surface to hold onto heat. Red indicates a surface material that retains its heat longer into the evening, suggesting differences relative to its surroundings. One possibility is that the materials that make up these soils and rocks have been more tightly bound together by mineral cements. The black oval indicates the targeted landing area for the rover, known as the “landing ellipse,” and the cross shows where the rover actually touched down at the Bradbury Landing site. An alluvial fan, or fan-shaped deposit where debris spread out downslope, has been highlighted in lighter colors for better viewing. This image was obtained by the Thermal Emission Imaging System on NASA’s Odyssey orbiter.  Image/caption credit: NASA/JPL-Caltech/ASU

“… where you now see the map of this feature called “thermal inertia”.  So we’re beginning to get a sense of what that might mean now, because – you see the “X” where Curiosity landed.  And you see high values of thermal inertia but not the highest values.  So we wonder what might cause this greater retention of heat.  And it could be because you’re dealing with materials that are consolidated. [Emphasis in voice – IWP]

“And what we haven’t told you today is anything about the rest of the payload – what we might measure in terms of the chemistry; what we might measure in terms of the mineralogy.  What we do know is: we go down towards Glenelg; we’re gonna go down towards that red patch, which is where the thermal inertia becomes the highest.  And so, our plan as we go forward now is to study the chemical and mineralogical attributes of these rocks, and see how water may relate to the cementation of these gravels to form a rock.

“And that’s really where it brings us, is to really the beginning of the science mission, where we have now discovered evidence for water, and what we’d like to do is to begin to characterize habitable environments [!!! EMPHASIS ADDED – IWPCHI].  And that requires using all of our payload, including the  instruments that measure the chemistry and the mineralogy.  So we’ll keep you updated as we go along with those measurements as well.”

[Sources:  USTREAM.TV,  “NASA Mars Rover News: Ancient River Streambed” Recorded live on September 27, 2012 12:46pm CST; NASA’s Mars Science Laboratory website.  All transcriptions of the Sept. 27th press conference were done by IWPCHI].

IWPCHI