Curiosity: Mars Science Lab Landing and Surface Operations

Gawdzilla said:
Anybody got a list of chemical compounds that are only or primarily made by living things?
Click to expand...
Exactly.

Curiosity's instruments can sample and analyze organic molecyles like amino acids, but finding them on Mars surface would not be conclusive evidence of life unless someone figures a way to demonstrate that they are necessarily endemic, and not originated from asteroids or comets which are known to have them. And Curiosity might analyze their chirality, but that's not conclusive evidence either because we know there's some extent of chirality in the asteroid stuff too.

SAM instrument could provide evidence of some other possible biomarkers, like some isotope ratios (e.g. C12/C13) but it would hardly provide conclusive evidence of life.

To put it simply for those entertaining the idea: Curiosity is not equipped to find life. Curiosity is not a life finding mission. It's not designed for it. It might be able to discover hypothetical macroscopic life like a Martian bunny rabbit hopping around in cameras. But not conclusive evidence of hypothetical living microbes.


ETA: Here's an image of the place in Rocknest where the scoops in question were obtained. It's just a wind blown sand dune. Part of the last one is still in the scoop: Five Bites Into Mars

And here's an informative presentation of SAM's capabilities to detect possible biomarkers: http://www.softconference.com/acschem/player.asp?PVQ=HJDL&fVQ=FJJKKJ&hVQ=
 
Last edited:
Its my guess that what has been found is evidence of a life form on Mars. A simple life form that might have evolved into something intelligent had a disaster not hit Mars.

I doubt seriously if the evidence is alive.
 
^ AGU's fall meeting Dec 3.-7. and more spefically AFAIK 5th.



Cainkane1 said:
Its my guess that what has been found is evidence of a life form on Mars. A simple life form that might have evolved into something intelligent had a disaster not hit Mars.
I doubt seriously if the evidence is alive.
Click to expand...
Well, let my gelsac be pierced on the spot if it was.
 
Last edited:
spin0 said:
Has been since 1277. Every now and then this same thing pops up like a "news" story. It's rather old news.
Click to expand...
What happened in 1277 to induce the RCC to adopt a policy on this question?
 
Craig B said:
What happened in 1277 to induce the RCC to adopt a policy on this question?
Click to expand...
During the medieval renessaince there appeared demarcation problems, and the Catholic Curch felt it needed sorting out. Part of that process were the Condemnations of Paris.

In 1277 the catholic bishop of Paris, Etienne Tempier condemned many doctrines he and the pope considered heretical or wrong. One of these condemned doctrines was the idea that the First Cause cannot make many worlds. It means that God, in his omnipotency, could very well have created more than one world (including life) and it was wrong to teach that it was impossible. This idea is known as the plurality of worlds and it has never since been considered wrong or heretical per se in the Catholic Church.

And for example in 1439 Nicholas of Cusa wrote in his book De docta ignorantia about many worlds and possible extraterrestial life on them. His ideas were not condemned by the Vatican, in fact the pope made Nicholas a papal envoy and later a cardinal.

So the ideas of possible extraterrestial life are rather old, and those ideas has been accepted in the Catholic church and in the Vatican for a very long time.

Here's an informative article about Nicholas of Cusa and extraterrestials: http://www.challzine.net/29/29extraterr.html (though the writer repeats some more recent myths about Bruno).
 
Last edited:
sphenisc said:
Am I right in thinking non-racemic samples are primarily associated with living things?
Click to expand...
Chirality would not be conclusive evidence of life as there has been some extent of chirality found in samples of asteroid/comet origin. It would work only if one could conclusively demonstrate that some particular amino acid's chirality cannot be of meteoroid origin, which would be very difficult - you'd have to collect a lot of samples of asteroids and comets to conclusively prove that.
 
Last edited:
spin0 said:
Chirality would not be conclusive evidence of life as there has been some extent of chirality found in samples of asteroid/comet origin. It would work only if one could conclusively demonstrate that some particular amino acid's chirality cannot be of meteoroid origin, which would be very difficult - you'd have to collect a lot of samples of asteroids and comets to conclusively prove that.
Click to expand...

Interesting. Is there a proposed mechanism for the origin of chirality in these samples? Are all the samples chiral in the same direction? Is this the same direction as in samples of biological origin?
 
spin0 said:
What Did Curiosity Find On Mars? | Exclusive Video Now, if that sample really was the "one for the history books" then I'd expect Curiosity to stop other activities and reanalyze the sample, and maybe even return to Rocknest where it was taken to get more such samples.
Click to expand...
Good point.

spin0 said:
SAM instrument isn't able to detect and identify genetic material, proteins, bacteria or tartigrades because it heats the samples to such high temperatures.
Click to expand...
Sigh.....:(
 
Soapy Sam said:
It used to be argued that if we found life on another planet , that would indicate that life is not a unique event on Earth, but abundant in the universe.

But as we know that meteoritic material from Mars has reached Earth in the past, it is perfectly possible life originated once - on Mars - and got here by rockmail, which puts us back to square one.

If life did get started on Mars though, I'd be very surprised if it is not still there in some form- and if Earth and Mars life started out from one source, it would surely be fascinating to see how different they are now. Of course, we would be comparing bacteria, not bison, but still fascinating.
Click to expand...
It's likely the genome of any Mars life form would suggest a markedly different origin or not. It wouldn't be proof, but it would be a strong indicator.

As for life originating on Mars first, it's a bizarre hypothesis, IMO. There's no reason to think life did not emerge on Earth. It's here, that's rather overwhelming evidence. Why people keep speculating it started elsewhere first reminds me of the gap god hypotheses.
 
Last edited:
sphenisc said:
Interesting. Is there a proposed mechanism for the origin of chirality in these samples? Are all the samples chiral in the same direction? Is this the same direction as in samples of biological origin?
Click to expand...
Very interesting. On the collected samples there seems to some bias to the same (L) direction as life on Earth has.

For example: Meteorites May Answer Life's Chirality Question
"In the new research, the team reports finding excess left-handed isovaline (L-isovaline) in a much wider variety of carbon-rich meteorites. “This tells us our initial discovery wasn’t a fluke; that there really was something going on in the asteroids where these meteorites came from that favors the creation of left-handed amino acids,” says Dr. Daniel Glavin of NASA Goddard. Glavin is lead author of a paper about this research published online in Meteoritics and Planetary Science January 17."

And one proposed mechanism for that observed bias is polarized UV-licht:
NON-RACEMIC AMINO ACID PRODUCTION BY ULTRAVIOLET IRRADIATION OF ACHIRAL INTERSTELLAR ICE ANALOGS WITH CIRCULARLY POLARIZED LIGHT
The delivery of organic matter to the primitive Earth via comets and meteorites has long been hypothesized to be an important source for prebiotic compounds such as amino acids or their chemical precursors that contributed to the development of prebiotic chemistry leading, on Earth, to the emergence of life. Photochemistry of inter/circumstellar ices around protostellar objects is a potential process leading to complex organic species, although difficult to establish from limited infrared observations only. Here we report the first abiotic cosmic ice simulation experiments that produce species with enantiomeric excesses (e.e.'s). Circularly polarized ultraviolet light (UV-CPL) from a synchrotron source induces asymmetric photochemistry on initially achiral inter/circumstellar ice analogs. Enantioselective multidimensional gas chromatography measurements show significant e.e.'s of up to 1.34% for (13C)-alanine, for which the signs and absolute values are related to the helicity and number of CPL photons per deposited molecule. This result, directly comparable with some L excesses measured in meteorites, supports a scenario in which exogenous delivery of organics displaying a slight L excess, produced in an extraterrestrial environment by an asymmetric astrophysical process, is at the origin of biomolecular asymmetry on Earth. As a consequence, a fraction of the meteoritic organic material consisting of non-racemic compounds may well have been formed outside the solar system. Finally, following this hypothesis, we support the idea that the protosolar nebula has indeed been formed in a region of massive star formation, regions where UV-CPL of the same helicity is actually observed over large spatial areas.
Click to expand...


And in light of these discoveries if SAM found amino acids their chirality in itself would not be conclusive evidence of hypothesized life on Mars. And UV hits Mars' surface too - though I don't know about it's polarization there. Maybe "wrong" R-chirality would be better evidence? I don't know.
 
Last edited:
^ By billions. They don't even do space travel. They just kwim. And you can't touch them. I think I'm going insane - today I saw no Martians.
 
spin0 said:
In 1277 the catholic bishop of Paris, Etienne Tempier condemned many doctrines he and the pope considered heretical or wrong. One of these condemned doctrines was the idea that the First Cause cannot make many worlds. It means that God, in his omnipotency, could very well have created more than one world (including life) and it was wrong to teach that it was impossible. This idea is known as the plurality of worlds and it has never since been considered wrong or heretical per se in the Catholic Church.

And for example in 1439 Nicholas of Cusa wrote in his book De docta ignorantia about many worlds and possible extraterrestial life on them. His ideas were not condemned by the Vatican, in fact the pope made Nicholas a papal envoy and later a cardinal.
Click to expand...

Even more remarkable then, that about two centuries later, a man who actually showed that the planets were in fact worlds, was branded a heretic by that same RCC!
 
Last edited:
smartcooky said:
Even more remarkable then, that about two centuries later, a man who actually showed that the planets were in fact worlds, was branded a heretic by that same RCC!
Click to expand...
Who?

ETA: No I'm serious: Who?
 
Last edited:
spin0 said:
Or vice versa: it is possible for life originated on Earth to have hitch hiked to Mars. It is possible for rocks to travel from Earth's surface to Mars, though Earth's gravity well is deeper and it doesn't happen as much.
Click to expand...
Plus, gravitationally it's "uphill" and Mars is a much smaller target. On the other hand anything infalling there hasn't the thick atmosphere to burn through and will have a lower impact velocity.
Mind you, it would be hilarious if "Curiosity" happened on a meteorite from Earth...
There's also another speculated way of travel: solar wind might blow microbes high in Earth's atmosphere out to space and towards Mars' orbit - but I think survival would be a challenge in that hypothesis. One might even speculate that hypothetical microbes high in Venus' atmosphere might be blown towards Earth's and Mars' orbits that way.

Yes, it would be very exciting discovery whether related or not to Earth's life. But if Mars had life we'd probably have to wait for future missions to provide conclusive evidence of it. Curiosity is not designed to provide that as it's mission objective is to study the enviroment and it's geological history, and give answers to the question: Has Mars ever had an enviroment that could have supported life (as we know it)?
Click to expand...
My guess is yes, early on- and I see no reason it could not survive deep down, but whether we'll find any trace on the surface is another matter.
 
Last edited:
spin0 said:
Besides hilarious would probably be significant finding - a more or less pristine sample of ancient Earth.
Click to expand...
Would it be recognizable? Do we know what the early Earth consisted of (atmosphere and composition) for sure?
 
You must log in or register to reply here.

Back
Top Bottom