Organic molecules found on Mars, MIT author says they are of “unknown origin”

NASA Finds Ancient Organic Material, Mysterious Methane on Mars

Discovery adds to evidence suggesting that Mars was at one time habitable.

This low-angle self-portrait of NASA’s Curiosity Mars rover shows the vehicle at the site from which it reached down to drill into a rock target called “Buckskin” on lower Mount Sharp. Credits: NASA/JPL-Caltech/MSSS

NASA’s Curiosity rover has found new evidence preserved in rocks on Mars that suggests the planet could have supported ancient life, as well as new evidence in the Martian atmosphere that relates to the search for current life on the Red Planet. While not necessarily evidence of life itself, these findings are a good sign for future missions exploring the planet’s surface and subsurface.

The new findings – “tough” organic molecules in three-billion-year-old sedimentary rocks near the surface, as well as seasonal variations in the levels of methane in the atmosphere – appear in the June 8 edition of the journal Science.

More here

From MIT:

While the new results are far from a confirmation of life on Mars, scientists believe they support earlier hypotheses that the Red Planet was once clement and habitable for microbial life. However, whether such life ever existed on Mars remains the big unknown.   

Since Curiosity landed on Mars in 2012, the rover has been exploring Gale Crater, a massive impact crater roughly the size of Connecticut and Rhode Island, for geological and chemical evidence of the chemical elements and other conditions necessary to sustain life. Almost exactly a year ago, NASA reported the discovery of such evidence in the form of an ancient lake that would have been suitable for microbial life to not only survive but flourish.

Now, scientists have found signs of complex, macromolecular organic matter in samples of the crater’s 3-billion-year-old mudstones — layers of mud and clay that are typically deposited on the floors of ancient lakes. Curiosity sampled mudstone in the top 5 centimeters from the Mojave and Confidence Hills localities within Gale Crater. The rover’s onboard Sample Analysis at Mars (SAM) instrument analyzed the samples by heating then in an oven under a flow of helium. Gases released from the samples at temperatures over 500 degrees Celsius were carried by the helium flow directly into a mass spectrometer. Based on the masses of the detected gases, the scientists could determine that the complex organic matter consisted of aromatic and aliphatic components including sulfur-containing species such as thiophenes. 

MIT News checked in with SAM team member Roger Summons, the Schlumberger Professor of Geobiology at MIT, and a co-author on the Science paper, about what the team’s findings might mean for the possibility of life on Mars.  

Q: What organic molecules did you find, and how do they compare with anything that is found or produced on Earth?

A: The new Curiosity study is different from the previous reports that identified small molecules composed of carbon, hydrogen, and chlorine. Instead, SAM detected fragments of much larger molecules that had been broken up during the high-temperature heating experiment. Thus, SAM has detected “macromolecular organic matter” otherwise known as kerogen. Kerogen is a name given to organic material that is present in rocks and in carbonaceous meteorites. It is generally present as small particles that are chemically complex with no easily identified chemical entities. One analogy I use is that it is something like finding very finely powdered coal-like material distributed through a rock. Except that there were no trees on Mars, so it is not coal. Just coal-like.

The problem with comparing it to anything on Earth is that Curiosity does not have the highly sophisticated tools we have in our labs that would allow a deeper evaluation of the chemical structure. All we can say from the data is that there is complex organic matter similar to what is found in many equivalent aged rocks on the Earth.

Q: What could be the possible sources for these organic molecules, biological or otherwise?

A: We cannot say anything about its origin. The significance of the finding, however, is that the results show organic matter can be preserved in Mars surface sediments. Previously, some scientists have said it would be destroyed by the oxidation processes that are active at Mars’ surface. It is also significant because it validates plans to return samples from Mars to Earth for further study.

Q: The Curiosity rover found the first definitive evidence of organic matter on Mars in 2014. Now with these new results, what does this all say about the possibility that there is, or was life on Mars?

A: Yes, previously, Curiosity found small organic molecules containing carbon, hydrogen, and chlorine. Again, without having a Mars rock in a laboratory on Earth for more detailed study, we cannot say what processes formed these molecules and whether they formed on Mars or somewhere in the interstellar medium and were transported in the form of carbonaceous meteorites. Unfortunately, the new findings do not allow us to say anything about the presence or absence of life on Mars now or in the past. On the other hand, the finding that complex organic matter can be preserved there for more than 3 billion years is a very encouraging sign for future exploration. “Preservation” is the key word, here. It means that, one day, there is potential for more sophisticated instrumentation to detect a wider range of compounds in Mars samples, including the sorts of molecules made by living organisms, such as lipids, amino acids, sugars, or even nucleobases.

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Marty

In other words what they found is consistent with the possibility that there was once life on Mars but is not evidence that there was actually life there.

DaveB

It may be fun science and gets the public engaged, which I agree is good; however I honestly believe it will be a fruitless search. Read Nick Bostrom’s, Oxford University, paper on the search for extraterrestrial life, “Where Are They? Why I Hope the Search for Extraterrestrial Life Finds Nothing.” Life on Earth has evolved so quickly, once it started, and yet so late in the age of the universe that it should have happened countless times over by now. And that life, with the same acceleration in evolution as experienced on Earth, could have reached great heights in technology. But where is it and what happened?

Tom in Florida

“And that life, with the same acceleration in evolution as experienced on Earth, could have reached great heights in technology. ”

Unless we are the first and the most advanced.

Edim
Felix

https://www.technologyreview.com/s/409936/where-are-they/

Even in 2008, his science was outdated.

Biochemists have gone far beyond the spontaneous synthesis of a few simple amino acids. Besides which, the building blocks of life occur naturally in meteorites.

The problem in origin of life research isn’t making complex amino, nucleic and fatty acids. It’s in bonding together into long chains (polymerizing) monomers, ie amino acids into proteins and nucleotides into DNA and RNA.

He’s also wrong about when life arose or arrived on Earth. It appeared about as soon as our planet cooled enough to maintain liquid water.

Out of hydrogen, the first generation of stars made carbon, oxygen, nitrogen, sulfur, phosphorous, iron and the other elements used by life. This took time. A supernova explosion some five billion years ago seeded with these elements the region of the galaxy in which the Sun formed.

It’s probable that microbes are common in our galaxy and the universe. The filter about which Bostrom speculates, if it exists, is likely to be multicellularity or intelligence. It could even be the transition from prokaryotes to eukaryotes, which apparently happened only once. Although colonial unicells abound (including the sperm-like ancestor of us metazoa), true multicellularity has happened only three times, in plants, fungi and animals.

If high civilizations have developed in the Milky Way, we might not be able to detect them due to distance, their demise or their relying on undetectable technologies. Humans are for instance in the process of switching from electromagnetic radiation-based communication systems to fiber optics. We might never stop radiating signals completely, but we’re liable to dial down our transmissions compared to the 20th century.

Much of the galaxy is inhospitable to life, but out here in the reaches where we live, there are likely to be other worlds with microbes. The conditions which permit relatively stable conditions for billions of years, allowing the evolution of multicells and civilization, however could be rare.

IMO life will indeed inevitably arise under the right conditions, but its subsequent evolution into more complex forms isn’t guaranteed. I’d venture that Mars has about even odds of having once harbored microbes, and that there is a finite possibility that it still does. Other candidate worlds in the solar system might enjoy even better odds. But if all other bodies in our system prove sterile, that doesn’t rule out life around other stars.

don k

Several problems actually, Felix. First some mechanism has to develop to produce self replicating compounds — quite likely RNA/DNA but conceptually they could be something quite different that eventually morphed into the RNA-DNA system — at least here on Earth. Second, there has to be a packaging system that somehow wraps the replication mechanism and it’s accoutrements into a fully self-replicating package.

OTOH, that possibly only has to happen once — somewhere in the galaxy — if it includes a mechanism for creating REALLY durable spores that can survive millions of years in space … and harbor a REALLY flexible and undemanding lifeform that can go forth and multiply in diverse environments.

Felix

It’s possible that life began only once in our galaxy, so has had ten billion years to develop and evolve, spreading throughout it. But IMO that’s less likely than repeated events using the Earth system or some other molecules for replication and metabolism.

The packaging issue isn’t a problem. As you know, lipids spontaneously form bilayer, spherical vesicles in water, thanks to having hydrophilic and hydrophobic ends. The lab of Nobel Laureate Jack Szotak has shown that these “soap bubbles” can not only contain proteins and nucleic acids, but split and take their contents with them. His team also has a plausible explanation for the evolution of modern phospholipid cell membranes.

So the outstanding problem in origin of life research isn’t membranes to contain the reactions and reactants of life, but how to polymerize the naturally-occurring monomers (amino acids and nucleotides) of large biological molecules (proteins, RNA, DNA, etc) without enzymes. Various such prebiotic processes have been demonstrated.

As per your suggestion, other replicating molecules are possible, both related to RNA and something entirely different.

JamesD

It’s the deadlock problem. DNA/RNA need proteins to be made and function. Proteins need DNA/RNA to be created and passed on. Dead lock.

And then there is the information problem. Shannon Entropy is a basic property in the universe. In fact Jaynes showed that Gibbs Entropy is derived from Shannon Entropy.

joelobryan

you seem unfamaliar with the RNA world hypothesis and ribozymes.

jarthuroriginal

Could you enlighten us regarding this hypothesis and ribozymes?

Felix

I will, if you don’t mind, my not being the well-informed Joel.

The short version is that RNA is capable of acting both as a store of genetic information and as a catalyst, ie an enzyme or “ribozyme”. Most enzymes are proteins (chains of amino acids) rather than nucleic acids (chains of nucleotides).

RNA is able to fold into complex shapes, which permits it to catalyze reactions in much the same way as proteins. DNA can’t do this, because it lacks one oxygen atom on its ribose (five-carbon) sugar. This however allows it to form its characteristic double helix, making it a more stable library of genetic information than RNA.

Thus, the RNA World Hypothesis suggests that life (self-replicating molecules) first emerged with RNA as both the information storehouse and the enzyme catalyzing metabolism. Prokaryotic cells of modern aspect then evolved to use DNA as the genetic library and proteins as the primary enzymes, with RNA conducting the translation, transcription and component transfer between the DNA and the ribosome, the site at which protein synthesis is carried out in modern cells. Ribosomes are composed about 2/3 of transfer RNA and 1/3 protein, but the key, active site is made of a type of tranfer-RNA.

You can easily learn more about it and other origin of life hypotheses on the Internet.

Felix

I should perhaps add that the RNA World was suggested as a simpler replication and protein synthesis mechanism than the complicate, Rube Goldberg apparatus in today’s cells.

The idea is that in a protocell, there need be no DNA to be translated, with introns to be snipped out and all the bells and whistles that go with modern reading of the genetic code and assembly of proteins. Strands of three nucleotide code-bearing RNA (gene sequences) could be read directly by shorter snippets of RNA, to which then the coded amino acid would attach, to be carried to a proto-ribosome, ie a glob of t-RNA, where the amino acids would be bonded together to form a polypeptide, ie a simple protein.

This system would have been mistake-prone, which is good for generating mutations to speed evolution, but generally bad for survival rate. So DNA evolved to take over the information storage function, requiring a more complex process of protein formation.

In origin, the system could have been even simpler, with an RNA ribozyme catalyzing its own replication reactions.

Felix

It’s not a deadlock. A variety of means have been experimentally demonstrated to break the apparent deadlock.

What’s left is just the chemical engineering problem of getting RNA to keep polymerizing faster than its oligomers break apart in water with only prebiotic enzymes to facilitate the synthesis.

RNA doesn’t need proteins to be created. It does however need enzymes or catalysts of some kind to form long chains, ie polymerize. It spontaneously forms short chains (oligomers) under a variety of conditions, and its component nucleotides (monomers) also self-assemble.

A nucleotide consists of a ribose sugar attached to a phosphate group (two in a chain) and a nucleobase, which in RNA is adenine, cytosine guanine or uracil (in DNA, replaced by thymine, made by methylation of uracil at the 5th carbon).

Felix

Uracil, one of the four nucleobases in RNA:

https://upload.wikimedia.org/wikipedia/commons/b/b4/Uracil.svg

Thymine, one of the four used in DNA (the other three being the same in both nucleic acids):

https://upload.wikimedia.org/wikipedia/commons/a/ab/Thymine_skeletal.svg

As noted, the only other difference between the two nucleic acids is that DNA’s sugar, deoxyribose, contains one less oxygen atom than RNA’s ribose.

Rud Istvan

Don K, I highly recommend the quite provocative book Seven Clues to the Origins of Life by Cairns-Smith. His ‘clay hypothsis’ is the onlynone I am aware that solves all the mutually reinforcing problems you cite.

Felix

His specific hypothesis is outdated now, but some origin of life scenarios currently still do incorporate mineral matrices or structures into the mix.

joelobryan

Binary neutron star collision is now a better bet than a supernova explosion for creating the abundance of heavier than iron elements on Earth, and bt association probably in theinner rocky planets and asteroids.

Felix

I know. But all the elements I mentioned are iron or lighter than iron, either made on the main sequence or in SN explosions.

Eustace Cranch

“Life” and “intelligent life” are two very different things. Life could very well be abundant in the universe, while sentient intelligence may be EXTREMELY rare. Evolution doesn’t inexorably lead to intelligence and technology. Horseshoe crabs, sponges, etc. have done fine for half a billion years or more. I seriously doubt we humans with our Big Brains will last that long. We’re just a tiny blip in Earth’s biological history.

Marty

David – As I understand it, bacterial life probably appeared within earth’s first half billion years. But the first intelligent technology capable species on earth (us) didn’t appear until 300,000 years ago.

So on earth life took about four billion years (give or take a few hours) for a technological civilzation to begin. To me that suggests that while life might be relatively common, technologically sophisticated intelligent life might be rare.

Witness the dinosaurs, who lived 130 million years (plus or minus a few hours) and apparently never developed intelligence. Because of the high metabolic cost of a large brain, evolution may select against intelligence.

It could very well be that we are the only intelligent species in the Milky Way that is capable of technology. Of course right now we have interesting arguments but no one knows.

Felix

You’re right. It’s quite possible that we are the only high technological species extant in our galaxy at this point in time.

The non avian dinosaurs existed for at least 170 million years (~236 to 66 Ma). Some of them were pretty smart, but not up to magpie and crow standards. Modern bird brains can do remarkable things with their reptilian brains, ie lacking the neocortex upon which mammals rely for higher functions.

jeanparisot

What’s more likely: another series of filter passes for life in another solar system, on another planet or moon in this system, or another species (octopus, whales, etc.) sparking sentient here.

Felix

Surely, but being smart isn’t enough. You also need to be able to manipulate the environment and pass on information to subsequent generations in order to build civilizations.

If civilization be possible in an ocean, then octopi are a good candidate. One problem however is that they only live about three years. They’re fascinating and scarily smart, with one central brain and eight peripheral ones, one in each arm.

Gamecock

“Life on Earth has evolved so quickly, once it started, and yet so late in the age of the universe that it should have happened countless times over by now.”

Once it started? Life on earth existed 3,000,000,000 years before evolution kicked in.

I do agree that minimalist life forms should be ubiquitous. There is nothing unique about earth. Maybe uncommon, but not unique.

“And that life, with the same acceleration in evolution as experienced on Earth, could have reached great heights in technology”

Not really. Extraterrestrial life would be constrained by the same physics as Man. Only so much is possible.

Felix

Evolution began as soon as life started, ie about four billion years ago on Earth.

In the first billion years, ie c. four to three billion years ago, amazing evolution occurred, to include the first photosynthetic bacteria. In the second billion years, sex definitely evolved, but also probably eukaryotes. If not then, then during the third billion years did eukaryotes evolve. In the fourth billion years, the multicellular kingdoms evolved, ie plants, fugi and animals, from among the eukaryotes. In the past half billion years, a plethora of plants, fungi and animals most wondrous to behold have evolved.

Latitude

they are looking inside a impact crater…..comets and meteors contain methane

Felix

Meteorites contain much more complex organic compounds than just methane.

Latitude

point was they are looking inside a crater…..and not considering what made the crater

Felix

Methane has been detected at at least three other sites around Mars, although impact craters large and small abound on the planet.

However, since asteroids contain organic compounds, it’s reasonable to assume that Mars also has indigenous hydrocarbon and even carbohydrate molecules.

But, sure, methane and more complex organics could well have arrived on the impacting meteor. Meteorites have delivered amino acids and other complex organic compounds to Earth.

rocketscientist

Yes, Mars does have methane. But not very much. All surveys so far indicate that the one thing that Mars has a dearth of is hydrogen. Carbon is in abundance (most of the atmosphere). But, absent hydrogen it remains … gasp! CO2.
Mars’ 2 moons however are a different story. Deimos is mostly carbonaceous chondrite. Its a fair guess that what ever event created these two odd-ball moons was responsible for leaving the hydrogen behind.

Felix

I’ve always supposed that the moons were captured asteroids, liable eventually to collide with the planet.

But maybe they are impact ejecta.

Mars has a supply of H on its surface, in the form of water ice caps, and under it lies more ice.

Felix

Given the low gravity and thin air on Mars, it’s no surprise that H2 is so rare and surface “soil” so low in hydrogen.

But the plentiful water ice remains a valuable resource with which to make hydrocarbons and carbohydrates. And O2, of course.

joelobryan

I’m guessing that Titan with its ethane seas has a lot of polymerized gunk that looks like kerogen. Life not required.

GregK

Methane derived from a comet or meteor is unlikely to have a seasonal flux.

There may be a non-biological source for the methane but it is certainly interesting

Johann Wundersamer

Yes,

Tom in Florida
“And that life, with the same acceleration in evolution as experienced on Earth, could have reached great heights in technology. ”

Unless we are the first and the most advanced.
___________________________________________________

But the basic question stays:

When the age of our universe is approximately

13,800,000,000.00 years

and anthropos history spans

2,000,000. to max. 4,000,000. years –

why now? why here?

Tom Halla

What a pity NASA did not install the proper instruments. It was probably a matter of mass restrictions.

rocketscientist

…and cost, and sophistication, and reliability, and lack of requirements….
shall I continue.
You cannot bring everything, so you make assumptions as to what is more useful, and then prioritize because, even everything you think you need to bring, can’t come.

I’m guessing you don’t “travel light”.

Red94ViperRT10

…and given the inertia of a bureaucracy, the design of this rover was probably finalized 30 years ago.

Felix
jarthuroriginal

Felix, you have a good sense of humor.

Gary Pearse

The mission was supposed to be a short one but here we are in 2018. The instrumentation was designed for months of roving if they were to be lucky.

Curiosity had a two year mission, but aspects of it, e.g. the RTG power source, can run for decades. Its mission has been extended indefinitely.

Perhaps you’re thinking of Spirit and Opportunity, three month missions starting in 2004. Opportunity is still running, Spirit got stuck and basically froze in 2010.

https://www.space.com/18769-mars-rover-curiosity-mission-extension.html

Leon Brozyna

Darn! And here I thought I cleaned up after myself the last time I visited (I still don’t know why everyone keeps wanting to visit the place … it’s a cold, dull, and dusty place).

Richard of NZ

How can it be cold? It has a higher atmospheric level of carbon dioxide than Earth measured both by %age and partial presssure.

Felix

As for seasonally changing methane levels:

https://gizmodo.com/curiosity-rover-finds-3-5-billion-year-old-organic-comp-1826637615

As for the methane, Curiosity’s Tunable Laser Spectrometer measured the methane levels in its surrounding atmosphere over five years. The levels averaged at 0.41 parts per billion by volume, but ranged from 0.24 to 0.65 depending on the season. Here on Earth, we associate methane with life, but it’s a mystery what could be causing it on Mars. Perhaps it’s some geologic process. “It probably indicates more active water in the subsurface than we understood,” scientist Kirsten Siebach, Martian geologist at Rice University not involved with the studies, told Gizmodo.

comment image

On Earth, we have a process by which underwater volcanoes interact with rock, producing methane that feeds bacteria. Maybe there are subsurface Martian bacteria eating that methane, Tanya Harrison, director of research for Arizona State University’s Space Technology and Science (“NewSpace”) Initiative, told Gizmodo. But for now, there’s no evidence for any such bacteria.

The methane is cool, whether it’s linked to life or not. “We thought Mars was dead internally,” Harrison said. “Now we have data to confirm that there’s a seasonal cycle, suggesting the methane is being generated by something.”

Wayne Townsend

Methane appears to be very common in the universe, even in places where there is unlikely to be life.

“Methane is widely distributed in the Solar System. In general, the inner planets are methane-poor, being Earth a unique exception, whereas the outer planets have CH4-rich atmospheres.”

Abstract of Methane in the Solar System by Andrés Guzmán-Marmolejo, Antígrna Segura

[http://boletinsgm.igeolcu.unam.mx/bsgm/vols/epoca04/6703/(2)Guzman.pdf]

joelobryan

Titan has seas of liquid ethane.

Felix

Some scientists entertain the possibility of Life As We Don’t Know It on Titan, with ethane as the solvent rather than water, which is a hard rock on the surface there. Titan also probably has a water ocean deeper down, in contact with a mineral core, comparable to those hypothesized for moons Europa and Enceladus.

James Beaver

Ancient organic material found. Send money…

I have a lot of respect for NASA/JPL teams but I’d like to see changes to financial laws to enable entrepreneur’s to make serious money off of space resources. THAT would really accelerate exploration. How about a tax free enterprise zone: everything built off planet is tax free for 50 years?

Felix

IMO looking for life on Mars is a legitimate state function. Before any humans go there, whether funded publicly or privately, we should try to make sure that it’s presently lifeless. Or not.

rocketscientist

Felix, …and then what? Not that I disagree, but IF we find life do we then institute a UN mandated “Prime Directive” to keep away? How will it be enforced? Does it even make sense given our history.
Life on Earth certainly didn’t observe any prime directive against populating wherever it landed. Only natural barriers existed (islands, canyons, rivers, mountain ranges, etc.) to separate the hardy form their neighbors. And, furthermore these barriers don’t exist for many different creatures. Fish can swim almost anywhere the water allows, and birds can fly over mountains and between islands. Once established in new territories, where competing, life would expand to allow the more robust to push aside the less. When occurring without the aid of humans we call this natural migration. If the rats swam between islands it is natural, but if they were transported between islands as stowaways then it is unnatural?
I do not subsequently ascribe to the “lets-get-there-first-and-trash-the-place” mentality either.
Somewhere in the middle is where we should be looking.

Felix

If the problems of interplanetary travel by humans can be solved, then IMO we should go there whether Mars be inhabited or not. But if microbes do live there now, explorers and settlers need to know that. It also means we have to be careful about the return trip, if any.

If methanogens exist there, they may well be harmless and even able to survive our arrival, but space travel planners would need to take them into account.

GregK

It’s likely that if there are microbes on Mars they are already here.
Our planet has “received” ejecta from Mars as a consequence of impacts on that planet.
We have evidence that microbes can survive outside the international space station. https://www.bbc.com/news/science-environment-11039206
They very likely could survive the trip from Mars to Earth.

Wayne Townsend

Since long-term space travel within the protective magnetosphere of the earth-moon environment is known to cause permanent changes to gene expression, [https://www.cnn.com/2018/03/14/health/scott-kelly-dna-nasa-twins-study/index.html] I have doubts that travel in the much more hazardous space beyond, with much more interesting radiation levels, will be solved soon. Even those promoting space tourism recognize that the early mars mission participants may all die.

rocketscientist

I was actually quite pleased that the professor from MIT wouldn’t chomp at the bait of the wishfully leading questions.

ResourceGuy

Who knows what all was sprayed off the shower of meteorite bombardment. The place is a pristine record of sky fall unlike the earth.

rocketscientist

I wouldn’t go so far as calling it pristine. Mars does have weather and erosion (due to wind). It is far less active than Earth, but not inert.

As to the concept of other bodies transporting these compounds, the idea that these organic molecules rained down from above, is still on the table.
The theory of “panspermia” http://panspermia-theory.com/ is quite attractive.

ResourceGuy

Okay, relatively pristine

Felix

True. Meteorites carry loads of organic compounds, to include amino acids, sugars, fatty acids and even nucleobases.

As you know, RNA and DNA are big molecules composed of nucleotides, ie compounds of a ribose (five-carbon) sugar with a nucleobase and a phosphate group attached, linked together by their sugar-phosphate backbones.

Latitude

They are looking inside a impact crater…..and didn’t eliminate the possibility it came in with the impact

Rud Istvan

The kerogen supposedly was found inside mudstones, so did not come from the impact.

ResourceGuy

Curiosity should have been kept at the gravel bar for longer to study all the rock types.

Rud Istvan

This is a fairly big deal. On Earth, kerogen derives from single celled photophynthetic marine organisms like cyanobacteria and algae. Kerogen shales form the source rock for oil and gas after catagenesis converts the kerogen into hydrocarbons under heat and pressure. It is suspected that cyanobacteria evolved on Earth before algae based on, e.g. , Australia’s stromatolite fossils, thought to be thick shallow water bacterial mats (in essence, biofilms).
Wonder if on a future mission a better kerogen sensor(s) could be incorporated, for example by Ramen spectroscopy with cyanobacteria like kerogen signatures?

TedL

A few weeks ago we saw news of the discovery of fossils in an outcrop of extremely old rock in Greenland. The fossils are stromatolites, characteristic formations left by mat-forming microbes. The rock is the oldest known bit of unaltered crust on the earth, dating some 3.8 billion years ago. Times were difficult, as this was the very end of the Late Heavy Bombardment, a period three hundred million years long during which the inner planets of the solar system where bombarded by large numbers of large asteroids and smaller debris. The heavily cratered surfaces of the Moon and Mercury are testament to the havoc. The Earth was equally battered, but most evidence has been since removed by plate tectonics and erosion. Water existed on the surface, but not as oceans, and the atmosphere lacked oxygen. Yet in this extraordinarily inhospitable environment, very simple forms of life emerged and began to colonize the world. This tells us that life is not fragile but extremely tough, and that it likely forms whenever and wherever suitable conditions persist.

We should keep this in mind when we listen to the likes of Elon Musk and the National Geographic talk about visiting Mars. In its early history Mars had a heavier atmosphere and shallow oceans of liquid water on its surface. Given the history of life on Earth, it is likely that microbial life also emerged on Mars. Mars lost its atmosphere billions of years ago, which also resulted in the loss of surface water, but there is good evidence of ice and liquid water beneath the surface. So what are the chances that the early Martian microbes adapted to the changing environment and survived to the present? They would be tough little things, adapted to harsh conditions and surviving on limited energy inputs. Imagine for a moment what they might do if a large warm wet nutrient-rich astronaut showed up at their microbial doorstep. My guess is that they would not be shy to take advantage of the opportunity and colonize this windfall. For its part the astronaut would have no natural defenses against a completely alien life form and could find itself easy prey to the Martians. This possibility makes me leery of any proposal to bring back samples from Mars, and reluctant to visit the planet in person. I suggest it would be prudent policy to make all trips to Mars one way only.

Felix

Samples of Mars have landed on Earth throughout our planet’s history, although granted, only after being blasted off it by violent impacts, then exposed to interplanetary radiation, cold and near vacuum for long periods.

don k

They’ll do that of course, but I think it’s more likely they’ll also collect some rock samples and send them home to Earth. My guess is that can be done for maybe $6B to $9B. Roughly three times the cost of a Mars Rover mission. (And a tiny fraction of the likely cost of the manned mission that is always a few decades in the future).

jarthuroriginal

Can kerogen be formed from processes not involving life?

Rud Istvan

Good question. Theoretically yes. And there are possibly some kerogen ‘signatures’ in intergalactic space. But in these localized quantities, probably not.

MarkW

OK, who farted?

Jeremy

I like NASA, but I really get the feeling I’m just being strung along to keep them just in my attention enough to maintain their funding levels. I think deep down, NASA knows they’re being replaced by the likes of SpaceX, as much as I may think Musk is misguided and personality-cult prone.

ResourceGuy

Save money–don’t send humans.

jarthuroriginal

and save lives.

bonbon

The Viking landers in 1976 found life – their Labeled Release findings are well known. Have a look at this :
https://www.nasa.gov/feature/goddard/2016/nasas-viking-data-lives-on-inspires-40-years-later
Why is this controversial, why the coverup?

Are we looking to a Marsgate?

Felix

The Viking experiment was by no means dispositive evidence for life on the surface of Mars. The reaction was probably just a result of the planet’s soil chemistry.

The 2020 mission should help clear things up.

bonbon

Metabolism, labeled with isotopes, was proven. It is certainly not settled, no matter what the “consensus”. Why did no later mission try this experiment again?
There is no instrument known what will register “life itself” as Kan’t would require, only what it does- metabolism. photosynthesis, chemosynthesis, polarization, chirality , etc…
It is enough of an issue that NASA hauled out all the old records – photo in link.
Here is the Viking Fact Sheet, scanned paper.
https://www.scribd.com/document/46167452/Viking-Fact-Sheet-May-1972
The scandal is they found metabolism and were forced to bury it.
Apollo was regarded as a stepping stone to Mars by von Braun, and was scrapped right at the time Viking hit the jackpot.

Life only comes from life – Redi’s principle is still valid. All efforts to effuse life from chemicals make the last alchemist Newton with his hypothses non fingo , look tame. They are exactly the same wrongheaded efforts to show an economy arises spontaneously, but in an unknowable way, from the friction of markets – von Hayek.
Somehow Viking planers and results put the spotlight on this nuttines.

Marsgate!

TheLastDemocrat

Any of those chemical processes defines life. OK.
This helps explain the reason for suppressing this, in 1972: Roe v. Wade could not have held the first trimester as a question mark regarding when “life” begins. -This chemical-reaction definition would put the beginning of human life within the first couple of hours of conception, for sure.

Felix

The surface of Mars is inhospitable to life. Doesn’t mean that hardy extremophile microbes couldn’t exist there, but they’d have to be extremely extreme.

https://www.scientificamerican.com/article/toxic-compounds-may-sterilize-martian-soil/

The story of the Labeled Release findings is complicated. Rather than recount and comment on it, this Wiki entry adequately tells the tale and continuing controversy, despite the consensus that metabolism wasn’t detected:

https://en.wikipedia.org/wiki/Viking_lander_biological_experiments

The Viking program wasn’t ended to hide a discovery of life, but because funding ran out. It was very expensive. We didn’t quit landing on the Moon in order to hide such a discovery. NASA would have loved to have been able to announce life, as they tried to do with the Martian meteorite from Antarctica under Clinton.

bonbon

Funding does not just run out – it is cancelled, not extended whatever, a political problem of optimism. After killing JFK, then Vietnam, they killed the Moon-Mars program – the utter breakdown is today evident in the opioid epidemic. Today this plague has NASA chief trying to sell the ISS!
Life from Viking’s instrument’s would have been inconvenient to this deconstruction.
POTUS has plans for the Moon – will he confront this process? He already has shaken it to its foundations – a wave of optimism is on the way led by China. Linking up in a Great 4 Powers approach will get us back on track.

GregK

There are tough little critters about somewhat more complex than microbes
Tardigrades are extremely extremely tough.

“Tardigrades can go into a hibernation mode, called the tun state, whereby it can survive temperatures from −272 °C (1 °C above absolute zero!) to 151 °C, vacuum conditions (imposing extreme dehydration), pressure of 6,000 atm as well as exposure to X-rays and gamma-rays”.

Crispin in Waterloo but really in Ulaanbaatar

Curiosity finds 5 Bucks on Mars

“CAPE CANAVERAL, FL—Stunned by both the sheer good fortune of their discovery and its implications for future exploration, scientists at NASA confirmed Friday that the Curiosity Rover had found five bucks in the red dust of Mars’ Gale Crater. “This is unbelievable—five whole American dollars!” said program director Jim Watzin, noting that the presence of a small bill suggests that future manned expeditions may one day be able to receive change back from cash transactions on Mars. “When the first lo-res images came back, we thought we’d found a 50—which would have been crazy, that’s too much to expect—but this is still amazing. None of the quarters we’ve found before, and certainly not the Canadian pennies, suggested the presence of any kind of decent life on Mars, but now that we’ve found a piece of currency we thought was actually worth the effort of picking up, we’re starting to think otherwise.” Watzin speculated that the fiver may eventually be regarded as the greatest extraterrestrial discovery since Apollo 15 found a small chest of Roman coins on the Moon.”
https://www.theonion.com/curiosity-rover-finds-5-bucks-on-mars-1826677179

bonbon

The way I heard it , 5 Loonies were found and Trudeau wants them back, but because of tariffs…

Wrusssr

Yes! NASA’s still discovering hints of life on Mars! Didn’t they hypothetically see dry river beds? Gullies? Where water once flowed? Wasn’t the water hypothesis sealed a few years ago with the discovery of rocks that had fallen to earth from the red planet that suggested as much? Haven’t they mathematically found a new heretofore undiscovered something more recently behind another planet or moon that might have water on it? And what about that petrified wood rock . . . wait . . . that was found somewhere else. Sorry. It’s almost getting to be too much for semi-literates (like myself) to keep up with. Anyone know if NASA solved its new shuttle’s instruments’ problems with the Van Allen Belts? You see the size of their new $100 million moon rover that was just cancelled? Lot smaller than their old jeep rover they had stored on the Eagle before it landed. Why would anyone cancel NASA’s space exploration, search for life . . . etc. . . .etc.

Dry river beds are a sign of life? Does that imply there must have been Martians who redirected the rivers to the canal system? I wonder what’s living in Saturn’s rings.

Afterthought

This is the problem with science-by-press conference. There is nothing here at variance with what is already known about Mars. They just want the unwarranted publicity and of course more taxpayer money. See also cosmology, climate science, sociology, medicine, anthropology, genetics etc etc etc.

Tom

“While not necessarily evidence of life itself, these findings are a good sign for future missions exploring the planet’s surface and subsurface.”
If NASA was being scientific, it would be neither good nor bad for future missions. If future missions don’t find life on Mars that is neither good nor bad it just is.

Javier

I think this is being hugely overplayed. Organic molecules have been discovered in comets and nobody thinks that means there is life in comets. This discovery is mildly interesting as it shows some organic molecules survive Mars conditions. But they could easily come from comets that impacted Mars. Their origin is still a mystery and perhaps they didn’t originate in Mars. Abiotic origin of organic molecules is pretty common. Pretty much you need methane, energy and reducing conditions. That Mars has oxydizing conditions, in my opinion, supports that they came from somewhere else.

Felix

We don’t know how old the organics are.

But lots of bodies in the solar system, galaxy and universe harbor organic molecules, not just simple hydrocarbons but complex carbohydrates. Asteroid meteorites deliver amino and fatty acids, sugars, nucleobases, etc to Earth.

Clouds in interstellar space contain polycyclic aromatic hydrocarbons, which are also found in meteorites from Mars:

https://www.windows2universe.org/physical_science/chemistry/PAH.html

Pat Frank

Kerogen is a name given to organic material that is present in rocks and in carbonaceous meteorites.

That is, the discovery is no evidence for Martian life. It’s evidence that organic material can survive a few billion years.

Sara

Mars has blue sunrises and sunsets. That was the reason I went there in the first place – that and meeting the Old Ones and asking about Willis. Just wanted to see the blue sunsets, and the hurtling moons of Barsoom.

I admit it – I took the tour, had a good time, had lunch with the Old Ones, and then left for Saturn’s Rings. No one has yet explained why they wobble so much, far more than Earth’s axial wobble. Weird, they are.

It was fun, but I had homework and I left my slide rule somewhere up there. If anyone finds it, would you let me know? I only screamed at the price when I bought it.

This shows that life can start anywhere. On Mars, it simply didn’t get a chance before a Big Rock From Outer Space whacked the red planet and blew the core out onto the surface. It was aliens did that. I saw them. I think it answers David Bowie’s question: is there life on Mars? Nope. Never really had a chance to go any further than chemical chains.

But if there’s methane up there, it can be a source of fuel, can’t it?

Mike Borgelt

Split the water ice, use the atmospheric CO2, Sabatier process and you have liquid methane and LOx i.e rocket fuel. That is the plan Musk wants to use. Bob Zubrin was first to propose this I think.

meiggs

The missions to the poles of Mars supposedly crashed. Interestingly in the most likely place active biology might still be underway. The politics are obvious and wrap a lil’ religion in with it and presto still can’t say if thar is life on Mars.” But NASA needs muney so tantalize the masses 4 a little mo’ of the tax haul…Elvis lives or maybe they b life on ….

Mike

From the damage that occurs to Astronauts in low earth orbit in a year, it would appear that Our life is biologically connected to the planet in ways we don’t understand. It is entirely possible that Humans cannot leave earth and survive.

Wrusssr

What!? How dare you suggest such a thing. Don’t you know we’ve been to the moon six or seven times circa ’60’s and 70’s? With technology reverse engineered from the Roswell saucers? In radiation-proof space ships? Sheesh . . .

bonbon

Yes, dumbness in space is lethal . Life left the oceans for land by packaging pieces of that ocean to being with them – pretty smart. Life quickly terraformed land. We already package a piece of our biosphere, bring it with us. Settling the surface (using abundant lava tunnel shielding) is easier than the vogage – that must be much faster. With fusion engines 3 weeks to Mars instead of 8 months with flare radiation toasting. The fuel for that, Helium3, in Lunar pole craters is already China’s stated target.

Felix

Life on icy “ocean world” moons in the solar system might be limited by essential nutrients such as phosphorus.

https://www.universetoday.com/139399/are-there-enough-chemicals-on-icy-worlds-to-support-life/

Phosphorus is essential to life as we know it, for instance in RNA, DNA and cellular membranes, but is not nearly as abundant in the universe as H, C, O, N and S. It is however, fairly plentiful in Earth’s crust.

An icy ocean world might not make enough P available for terrestrial-style life to develop, or if it did, to thrive ubiquitously. Thus, finding organisms on Jovian moons Ganymede, Callisto and Europa or Saturnian moons Enceladus and Titan could be hit or miss.

Ken L

The significance, in my view, of the information from the press conference is that up to now they had no great reason to believe they would be able to find organic molecules from any source and thus it might be extremely difficult, if not impossible, to find evidence of life. Now they know it’s possible and can proceed in the quest with some hope of locating organic based evidence that they analyze as to its origins. And don’t forget the discovery of the cyclic methane spikes which may offer intriguing hints of a process.

Ken L

Apologies for the off topic location of my comment, Felix. I was confused by the new format. I have it figured out now, however :).

Felix

Doesn’t seem out of place to me.

JamesD

Proof of abiogenic source for petroleum.

joelobryan

Titan is proof of that.

The whole concept of “Organic Geochemistry” is totally wrong, also on Earth. Although compounds made with carbon and sufur and hydrogen, etc. have sorted under the banner of being ‘organic’, they don’t actually need to be produced by live organisms. Processes inside the Earth and Mars also produce such substances in abundance, via INORGANIC means (processes). We, therefore need a paradigm change to get the organic hunters ‘down to Earth’. We need to change the definition of organic chemistry.

Felix

“Organic” in chemistry just means reactions involving carbon.

The key distinction for biochemistry v. geochemistry is between biotic and abiotic carbon chemistry.

bonbon

The latest archaeological (and forensic) dating method, amino acid racemization, works using Pasteurs famous discovery of favored polarization of molecules resulting from a living process. I would hope NASA sends instruments with at least Pasteur’s principle built in. Why life prefers this asymmetry is not known, and only Vernadsky tried to look at it – somewhen this solar system went through an asymmetric region or process around the galaxy. One possibility is the higly polarized process of solar system formation. That is why it is extremely important to find the earliest evidence of metabolism around 4billion years.
http://www.pnas.org/content/115/1/53
Those “squiggles” might look very like the Antarctic Mars meteor micro fossils.
The “controvery” gets frothy because it seems life is built in, a universal principle, does not ooze from muddy alchemy. Imagine – a knowable principle !

Jim

If you have a lot of carbon, oxygen, hydrogen and other atoms around, some of them will combine to produce “organic molecules”. It’s chemistry. Doesn’t mean the environment either had or was conducive to life.

David Walton

davidbennettlaing

The most effective way to determine whether organic chemicals on Mars were created by organic or inorganic processes is to examine any enantiomorphic forms for preferred chirality. On Earth, organic processes have almost always produced levorotatory chirality, but dextrorotatory chirality would also have been possible. The important thing is that, in order to qualify for organic origin, enantiomorphic organics should all show one dominant chirality, either left-handed or right-handed.

davidbennettlaing

The most effective way to determine whether organic chemicals on Mars were created by organic or inorganic processes is to examine any enantiomorphic forms for preferred chirality. On Earth, organic processes have almost always produced levorotatory chirality, but dextrorotatory chirality would also have been possible. The important thing is that, in order to qualify for organic origin, enantiomorphic organics should all show one dominant chirality, either left-handed or right-handed.

davidbennettlaing

The most effective way to determine whether organic chemicals on Mars were created by organic or inorganic processes is to examine any enantiomorphic forms for preferred chirality. On Earth, organic processes have almost always produced levorotatory chirality, but dextrorotatory chirality would also have been possible. The important thing is that, in order to qualify for organic origin, enantiomorphic organics should all show one dominant chirality, either left-handed or right-handed.