Author Topic: FEATURE: Curiosity confirms organics on Mars; Opportunity’s 10 year anniversary  (Read 81084 times)

Offline Dalhousie

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Chris McKay (who is on the Curiosity team) and Penny Boston (who isn't), both leading astrobiologists commented favourably on the paper.  http://www.astrobio.net/news-exclusive/potential-signs-ancient-life-mars-rover-photos/
Apologies in advance for any lack of civility - it's unintended

Offline Torbjorn Larsson, OM

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I would add to Anderson's writ that Vasavada rejects Noffke's claim that there are no potential confusions (false positives) at her state of checking off on her MISS tests list, on Earth. (She do want to make a complementary microanalysis and a search for potential false positives, to make sure.) Either Vasavada makes a blanket claim that Noffke is wrong, or he has observations that would teach MISS experts something new.

In either case it would be useful, not least for strategies on rover science, if Vasavada wrote a counter-article that lays out his evidence for errors or Mars's unique MISS-like geological processes.

Can Curiosity's team really leave this behind as "a causal dismissal", especially since the 2020 rover isn't finalized? Any thoughts?

I don't think Vasavada has any personal competence to assess Noffke's paper.  He is not a geologist, let alone a palaentologist, has not done any field work on any planet, he's a physicist and a modeller.

Of course here I assume he is speaking for the team.  Right or wrong the team, including people who were competent to make the call decided that these features were not worth a closer look.  It's too far away in time and space to go back and check again.

All they can do is perhaps be a bit more alert to the possibility, should they see similar features, and perhaps look more closely.


Thanks for the response! So they are playing ass covering politics by inserting the unnecessary "probably". That is a shame. [Here I am, speculating all the same. But I feel provoked by their overreach.  ???]

Noffke has been on record (in the web interview I think) that she saw similar features later in the traverse but in so bad condition so she wouldn't have wanted to write a paper about it.

Possibly they surface in the climb after passing the current lake sediments, if the fossilization was so extensive.

I don't see any impact for the 2020 mission myself, beyond a pointer to the possibility of returning microbial textures.

It could, probably should, be used to weight similar lakes but especially playa environments into the landing ellipse (the survey area in that case). Else it will be more a geological than a biological mission again. (It need to be both for biology's sake, but one can always argue the best balance.)

I assume it is too late to modify the instrument set (to go through Noffke's microanalysis requirements in situ if possible). Especially since it would be speculative based on tentative findings. That would be more an argument against the pushing of planetary missions against each other so that one can't inform the construction of the next.
« Last Edit: 01/15/2015 10:34 am by Torbjorn Larsson, OM »

Offline Torbjorn Larsson, OM

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Chris McKay (who is on the Curiosity team) and Penny Boston (who isn't), both leading astrobiologists commented favourably on the paper.  http://www.astrobio.net/news-exclusive/potential-signs-ancient-life-mars-rover-photos/

Yeah, that is what I referred to earlier. But I would say that McKay is favorable on the paper but neutral on its findings, Boston is gushing on the latter.

Offline Vultur

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Why doesn't NASA send an actual life detection mission? The state of the art in microbiology & especially extreme environments has advanced so much since Viking it isn't even vaguely comparable (they didn't even know about chemosynthesis when those experiments were designed!)

Offline QuantumG

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Why doesn't NASA send an actual life detection mission?

Because there's nothing there.

Everyone knows there's nothing there. That's why the goal has shifted to "evidence of fossil life" and other nonsense.
Human spaceflight is basically just LARPing now.

Offline Tetrakis

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As someone who runs gas chromatography/mass spectrometry experiments quite a bit, I was initially skeptical of the detection of martian chlorobenzene and other chlorinated hydrocarbons. I'm accustomed to seeing all sorts of polychlorinated/polysilylated organics coming through the GCMS as "noise" resulting from traces of manufacturing lubricants or solvents.

Then again, the isotope ratios in the organics is pretty convincing. Accepting that the organics originate on Mars, it surprises me that an appropriately reducing environment which would allow for the formation of hydrocarbons could be so oxidized to be full of what is, for all intents and purposes, bleach. Is there literature on how an environment devoid of free oxygen could produce hypochlorite or perchlorates? Where did the evidently high levels of Martian perchlorates come from?
« Last Edit: 01/17/2015 04:17 am by Tetrakis »

Offline the_other_Doug

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That has been what has been niggling at the back of my mind for a while.  The oxidation of the Earth's surface materials that is still strongly seen in many exposed oxidized iron-bearing strata across our globe only began after the "great oxygen catastrophe" that occurred after photosynthetic life evolved and changed the basic chemistry of our atmosphere.

Could the oxidized mineralogy seen on Mars have happened in the absence of abundant free oxygen in the early Martian atmosphere?  And if not, then what besides photosynthetic life could have caused Mars' own oxygen catastrophe?
-Doug  (With my shield, not yet upon it)

Offline Tetrakis

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Brief Googling seems to have placed me at the top of "Mount Stupid":

http://faculty.washington.edu/dcatling/Catling2010_AtacamaMarsPerchlorate.pdf

The gist of the paper is that ancient volcanic chlorine and/or ongoing photochemical generation of oxidizing species (O, superoxide, H2O2, O3) in the arid environment should be sufficient for the observed levels of perchlorate on Mars. There is little direct evidence for this atmospheric photochemistry on Mars, though, because the oxidizing species in question are both low in concentration (even relative to methane) and short-lived. Especially eye opening is that similarly high levels of perchlorate can be found in the Atacama desert.

Offline Vultur

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Why doesn't NASA send an actual life detection mission?

Because there's nothing there.

Everyone knows there's nothing there. That's why the goal has shifted to "evidence of fossil life" and other nonsense.

Um... based on what? Endoliths could probably survive on current Mars just fine, if there's even tiny traces of water subsurface. Their requirements are extremely small (and being subsurface, the UV won't bother them).

I see absolutely no reason to think that current life on Mars is unlikely.

EDIT: And anyway, NASA hasn't even sent a lander/rover that could look for evidence of fossil life!
« Last Edit: 01/18/2015 07:17 pm by Vultur »

Offline whitelancer64

Why doesn't NASA send an actual life detection mission?

Because there's nothing there.

Everyone knows there's nothing there. That's why the goal has shifted to "evidence of fossil life" and other nonsense.

Um... based on what? Endoliths could probably survive on current Mars just fine, if there's even tiny traces of water subsurface. Their requirements are extremely small (and being subsurface, the UV won't bother them).

I see absolutely no reason to think that current life on Mars is unlikely.

EDIT: And anyway, NASA hasn't even sent a lander/rover that could look for evidence of fossil life!

the bigger problem is that we STILL don't have a definitive chemical signature that we can point to and say "look! here is life!"

there is no magical "life detection" box that we could send to Mars yet. yes, the technology we've got today is much better than it was for Viking, but there is still no consensus for what needs to be looked for when we are searching for life. the proposed instruments that we'd use to search for life have lots of limitations.

and i'd argue that NASA has sent both landers and rovers that can look for evidence of fossil life, or even current life, anything that is within their capabilities to see, they could find. Curiosity's MAHLI is capable of taking images 13.9 microns per pixel, for example, and there are lots of life-forms here on Earth that are larger than that.
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"There are lies, damned lies, and launch schedules." - Larry J

Offline pagheca

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Why doesn't NASA send an actual life detection mission?

Because there's nothing there.

Everyone knows there's nothing there. That's why the goal has shifted to "evidence of fossil life" and other nonsense.

Um... based on what? Endoliths could probably survive on current Mars just fine, if there's even tiny traces of water subsurface. Their requirements are extremely small (and being subsurface, the UV won't bother them).

I see absolutely no reason to think that current life on Mars is unlikely.

EDIT: And anyway, NASA hasn't even sent a lander/rover that could look for evidence of fossil life!

QuantumG may have stretched a bit the conclusions, but the number of (informed) scientists thinking there is life on Mars is marginal shrinking (when one exclude those with a conflict of interest. :) )

The point is that repeating ad nauseam that there MAY be life on Mars doesn't make life more likely.
« Last Edit: 01/18/2015 08:51 pm by pagheca »

Offline Vultur

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the bigger problem is that we STILL don't have a definitive chemical signature that we can point to and say "look! here is life!"

there is no magical "life detection" box that we could send to Mars yet. yes, the technology we've got today is much better than it was for Viking, but there is still no consensus for what needs to be looked for when we are searching for life. the proposed instruments that we'd use to search for life have lots of limitations.

Sure, it's not an easy problem, but that's no reason not to try. Viking tried with what was available back then; the field has advanced to the point that I think it's time to try again.

If Mars life is nucleic acid based (which seems not unlikely) it should be (comparatively) easy to unambiguously identify. If not, the best route IMO would be to look for really complex organic molecules with structures that suggest "biomolecules" (with a non-heating-based method like a Raman spectrometer, not SAM - which I think ExoMars and Mars 2020 are supposed to have).

Quote
and i'd argue that NASA has sent both landers and rovers that can look for evidence of fossil life, or even current life, anything that is within their capabilities to see, they could find. Curiosity's MAHLI is capable of taking images 13.9 microns per pixel, for example, and there are lots of life-forms here on Earth that are larger than that.

Sure, but the life wouldn't be on the surface due to UV - it would be subsurface, maybe shallow, but not exposed. You have to scoop and drill.

Microfossils or stromatolite-type things might be found, but identifying them unambiguously enough to convince the scientific community from a MAHLI image alone seems unlikely.

QuantumG may have stretched a bit the conclusions, but the number of (informed) scientists thinking there is life on Mars is marginal shrinking (when one exclude those with a conflict of interest. :) )

Yeah, but unless it's based on evidence, that doesn't mean anything. When you look at the sort of conditions endoliths and some sub-surface microbes in Antarctica live in, and compare them to conditions likely under the Martian surface, I don't see why life should be unlikely.

Life developed really fast on Earth, so Mars's brief period of more or less 'earthlike' conditions probably isn't a barrier to life starting. The questions are: how likely is the origin of life, and how quickly could primitive life develop an endolithic/subsurface mode of life?

(and that doesn't even consider endolith transfer from Earth to Mars via meteorites...)

Offline hop

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QuantumG may have stretched a bit the conclusions, but the number of (informed) scientists thinking there is life on Mars is marginal shrinking (when one exclude those with a conflict of interest. :) )
I don't think much of the community would dismiss the possibility of life hanging on somewhere, but virtually none would expect it to be the just kicking around in loose surface regolith. If there's life, it's almost certainly underground and mostly isolated from the surface.

For a life detection mission to be justified, there would need to be a compelling case that a specific, accessible environment was presently habitable.

The other thing the "why hasn't NASA..." question misses is how NASA science missions are actually selected. The broad science goals of NASA led missions defined by the science community, through the decadal survey.

The decadal put priority on sample return, not some "life detection" mission, so NASA can't just go out and decide to send a life detection mission. Someone could propose one for Discovery, but without a compelling target it would have no chance of selection, and plausible targets would likely exceed Discovery budget.

Offline whitelancer64

the bigger problem is that we STILL don't have a definitive chemical signature that we can point to and say "look! here is life!"

there is no magical "life detection" box that we could send to Mars yet. yes, the technology we've got today is much better than it was for Viking, but there is still no consensus for what needs to be looked for when we are searching for life. the proposed instruments that we'd use to search for life have lots of limitations.

Sure, it's not an easy problem, but that's no reason not to try. Viking tried with what was available back then; the field has advanced to the point that I think it's time to try again.

If Mars life is nucleic acid based (which seems not unlikely) it should be (comparatively) easy to unambiguously identify. If not, the best route IMO would be to look for really complex organic molecules with structures that suggest "biomolecules" (with a non-heating-based method like a Raman spectrometer, not SAM - which I think ExoMars and Mars 2020 are supposed to have).

Quote
and i'd argue that NASA has sent both landers and rovers that can look for evidence of fossil life, or even current life, anything that is within their capabilities to see, they could find. Curiosity's MAHLI is capable of taking images 13.9 microns per pixel, for example, and there are lots of life-forms here on Earth that are larger than that.

Sure, but the life wouldn't be on the surface due to UV - it would be subsurface, maybe shallow, but not exposed. You have to scoop and drill.

Microfossils or stromatolite-type things might be found, but identifying them unambiguously enough to convince the scientific community from a MAHLI image alone seems unlikely.

i'm not saying that we shouldn't send "life detection" type experiments to Mars, we absolutely should. but you need to not set them up as a "life detection" mission - because they won't be that.

the simple answer to your question "Why doesn't NASA send an actual life detection mission?"

is that we don't have any simple answers to the questions "what is life?" and "how do we detect life?"

so you need to set up the expectations for such a mission to be realistic. there is no magical "life detection" box we can send to Mars. any such experiments would have sets of strengths, weaknesses, and limitations.

for example, if the Life Marker Chip (LMC) experiment were sent to Mars, its detector is based on antibodies that react to very well understood immune functions - and would do very, very well at detecting life here on Earth. so if Mars life is similar to Earth life, it has a good chance to detect it. but if not, it won't detect Mars life, even if it is there.
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"There are lies, damned lies, and launch schedules." - Larry J

Offline Dalhousie

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Why doesn't NASA send an actual life detection mission?

Because there's nothing there.

Everyone knows there's nothing there. That's why the goal has shifted to "evidence of fossil life" and other nonsense.

We don't know that there is nothing there.  There is a good chance that there once was life, and a lower chance it is still there.
Apologies in advance for any lack of civility - it's unintended

Offline Dalhousie

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Why doesn't NASA send an actual life detection mission?

Because there's nothing there.

Everyone knows there's nothing there. That's why the goal has shifted to "evidence of fossil life" and other nonsense.

Um... based on what? Endoliths could probably survive on current Mars just fine, if there's even tiny traces of water subsurface. Their requirements are extremely small (and being subsurface, the UV won't bother them).

I see absolutely no reason to think that current life on Mars is unlikely.

EDIT: And anyway, NASA hasn't even sent a lander/rover that could look for evidence of fossil life!

QuantumG may have stretched a bit the conclusions, but the number of (informed) scientists thinking there is life on Mars is marginal shrinking (when one exclude those with a conflict of interest. :) )

The point is that repeating ad nauseam that there MAY be life on Mars doesn't make life more likely.

I don't think the number scientists that think there might be life on Mars is shrinking.  If anything its increasing.
Apologies in advance for any lack of civility - it's unintended

Offline Star One

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Why doesn't NASA send an actual life detection mission?

Because there's nothing there.

Everyone knows there's nothing there. That's why the goal has shifted to "evidence of fossil life" and other nonsense.

Um... based on what? Endoliths could probably survive on current Mars just fine, if there's even tiny traces of water subsurface. Their requirements are extremely small (and being subsurface, the UV won't bother them).

I see absolutely no reason to think that current life on Mars is unlikely.

EDIT: And anyway, NASA hasn't even sent a lander/rover that could look for evidence of fossil life!

QuantumG may have stretched a bit the conclusions, but the number of (informed) scientists thinking there is life on Mars is marginal shrinking (when one exclude those with a conflict of interest. :) )

The point is that repeating ad nauseam that there MAY be life on Mars doesn't make life more likely.

I don't think the number scientists that think there might be life on Mars is shrinking.  If anything its increasing.

Precisely that was my reading of the situation as well. Not sure where the OP got the idea from that it was shrinking number and would in fact ask them to present some kind of evidence to back up that statement so counter to the actual situation is it.

Offline pagheca

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Precisely that was my reading of the situation as well. Not sure where the OP got the idea from that it was shrinking number and would in fact ask them to present some kind of evidence to back up that statement so counter to the actual situation is it.

Just an impression, I will candidly admit that. I spoken with several colleagues about that in some occasions and I got the impression that a lot of professional astronomers, if obliged to bet, would now say there is no life at present on Mars (maybe in the past) after some past bandwagon effect.

This is not enough to say "there is no life at present on Mars", neither to conclude the number of scientists believing there is is shrinking, but I got the impression that the general public is much more positive about the idea (again: life on Mars TODAY) than informed scientists.

Now, by looking to the internet to investigate more about this quite interesting issue (what planetary scientists think about the chance of life on Mars), I found a 2005 Nature paper saying that

Quote
An informal poll of 250 scientists attending the Mars Express Science Conference at Noordwijk in the Netherlands last month revealed how high their hopes have climbed. About three-quarters think life could have existed on Mars in the past, and a quarter think life could be there today.

So, apparently at the time - almost 10 years ago, therefore before most of the rovers works came out - the number was rather increasing. It would be very interesting to check the number now at a similar intl. conference.  However, this was people attending a "Mars Express" conference, so, highly tied to this hope.

STANDARD DISCLAIMER: just to clarify, I'm not interested in defending one or the other position, and I'm ready - as always - to change opinion or even to renounce to an opinion. At the end of the day, what scientists believe is less relevant than what they know, but up to when the limited, available funding must be directed toward one or other competitive targets.

My impression is, again, that this "life on Mars" thing has been quite pimped up in the past to obtain more funding (example: don't be a Venus planetologist today, as your chances to get funded are quite dimmed) and because was obviously nice meat for the general media. Every single result was immediately accompanied with the claim that this show that look! There MAY BE life on Mars (look for example at that methane fluctuation issue), stretching evidences and transforming an hypothesis almost in a certainty by talking about that over and over.

Please read carefully what I said. I'm not embracing one or another position on this quest at this point, but I rather think it's very difficult to be unbiased after so much continuous talking about life on Mars. I always feel like whatever I think it's because I'm biased.
« Last Edit: 01/19/2015 09:14 am by pagheca »

Offline Star One

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Precisely that was my reading of the situation as well. Not sure where the OP got the idea from that it was shrinking number and would in fact ask them to present some kind of evidence to back up that statement so counter to the actual situation is it.

Just an impression, I will candidly admit that. I spoken with several colleagues about that in some occasions and I got the impression that a lot of professional astronomers, if obliged to bet, would now say there is no life at present on Mars (maybe in the past) after some past bandwagon effect.

This is not enough to say "there is no life at present on Mars", neither to conclude the number of scientists believing there is is shrinking, but I got the impression that the general public is much more positive about the idea (again: life on Mars TODAY) than informed scientists.

Now, by looking to the internet to investigate more about this quite interesting issue (what planetary scientists think about the chance of life on Mars), I found a 2005 Nature paper saying that

Quote
An informal poll of 250 scientists attending the Mars Express Science Conference at Noordwijk in the Netherlands last month revealed how high their hopes have climbed. About three-quarters think life could have existed on Mars in the past, and a quarter think life could be there today.

So, apparently at the time - almost 10 years ago, therefore before most of the rovers works came out - the number was rather increasing. It would be very interesting to check the number now at a similar intl. conference.  However, this was people attending a "Mars Express" conference, so, highly tied to this hope.

STANDARD DISCLAIMER: just to clarify, I'm not interested in defending one or the other position, and I'm ready - as always - to change opinion or even to renounce to an opinion. At the end of the day, what scientists believe is less relevant than what they know, but up to when the limited, available funding must be directed toward one or other competitive targets.

My impression is, again, that this "life on Mars" thing has been quite pimped up in the past to obtain more funding (example: don't be a Venus planetologist today, as your chances to get funded are quite dimmed) and because was obviously nice meat for the general media. Every single result was immediately accompanied with the claim that this show that look! There MAY BE life on Mars (look for example at that methane fluctuation issue), stretching evidences and transforming an hypothesis almost in a certainty by talking about that over and over.

Please read carefully what I said. I'm not embracing one or another position on this quest at this point, but I rather think it's very difficult to be unbiased after so much continuous talking about life on Mars. I always feel like whatever I think it's because I'm biased.

Which is not the impression of what your position was in your OP. Nor does one singular informal poll prove much of a data baseline to extrapolate any change of belief in the matter. As for the rest well we'll just have to agree to disagree on the reading of the situation.

Offline pagheca

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Which is not the impression of what your position was in your OP.

That's right. In fact I wrote "I'm not embracing one or another position on this quest at this point".

I am not afraid of changing opinion based on new evidences. Nobody should if based on scientific reasoning.
« Last Edit: 01/19/2015 10:18 am by pagheca »

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