Mars' Microbial Secrets: Potential Biosignatures Uncovered

This is Spacetime Series twenty eight, Episode one hundred and eleven, well broadcast the fifteenth of September twenty twenty five. Coming up on Spacetime, discovery of potential bias signatures on Mars, an atmosphere discovered on the frozen distant world of Make Marke, and a total lunar eclipse wows half the world. All that and more coming up on space Time. Welcome to space Time with Stewart Gary. Scientists with NASA claim that sample was collected by the Mars Perseverance Rover from an ancient dry river bed in Jezroe Crater might be the best chance yet of discovering preserved evidence of past microbial life on the Red planet. A report in the journal Nature claims the samples, called Sapphire Canyon were collected from a rock named Shiaba Falls last year, and the studies authors believe these rocks could contain potential bios signatures. A potential bios signature is a substance or structure It just may have biological origin, but requires more data or further study for a conclusion can be reached about the presence or absence of life. Safaire canyons one of twenty seven rock cores, which Perseverance has collected since Lanting and jezro Crator in February twenty twenty one. Now, as we reported on this show at the time, Perseverance came upon che Avia Falls back in July last year while exploring the Bright Angel Formation, a set of rocky outcrops on the edges of theu Retra Valley is an ancient river valley measuring some four hundred meters wide that was carved by water rushing into jeesro Crator long ago. This new paper represents a peer reviewed study of those original results. That's basically saying, yeah, you could have something there, Darence. The scientific instruments found the formation sedimentary rocks were composed of clay and silt, which on Earth are excellent preservers of past microbial life. They're also rich in organic carbon, sulfur, oxidized iron otherwise rust, and phosphorus. Chowba Falls is an arrowhead shaped rock measuring about a meter long and sixty centimeters wide. As they were examining it, Situs noticed what appeared to be colorful spots. Now, the spots on the rock could have been left behind by microbial life if that life had been using the raw ingredients that is, the organic carbon, the sulfur, and the phosphorus in the rock as an energy source. And when the. Scientists gained higher resolution images, they found a distinct pattern of minerals arranged in what are known as reaction fronts, points of contact where chemicals and physical reactions occur. This pattern has been named the lepid spots, and it counted the signature of two iron rich minerals, vivian Night, which is a hydrated iron phosphate, and grig Eyte, which is an iron sulfide. Vivianarde is frequently found on Earth in sediments, heat bogs, and around decaying organic matter, and importantly, here on Earth, at least certain forms of microbial life can produce grigte. The combination of these minerals, which appear to have been formed by electron transfer reactions between the sediment and organic matter, is a potential fingerprint for microbial life which would have used these reactions to produce energy for growth. But the thing is these same minerals can also be generated without the presence of life, including sustained high temperatures, cidic conditions, and binding by organic compounds. However, the rocks of Bright Angel don't show evidence that they have experienced any high temperatures or acidic conditions, and it's unknown whether the organic compounds present would have been capable of catalyzing the reaction at low temperatures. The discovery was especially surprising because. It involves some of the youngest sedimentary rocks that perseverances so far investigated on Mars. Earlier hypotheses have assumed that signs of ancient life on the red planet would be confined into older rock formations, but it's new finding suggests that Mars could have been habitable for much longer periods of time alternatively much later in the planet's history than previously thought, and that the older rocks may also hold signs of life, but signs which is simply much harder to detect. Acting Natural Administrator Sean Duffy says the findings are the closest scientists have come so far the discovering life on Mars. Duffy says the identification of a potential bias signiature on the red planet is a groundbreaking discovery and one that will advance sciences understanding of Mars. For the last thirty years, NASA has been exploring Mars, and in that exploration we're looking for signs of life. We're looking for water. But thirty years of exploration and in the past we thought we found signs of life. And when we did that, we put it out to the scientific community, and the scientific community would come back and say, well, listen, there's different explanations for what you think was life. It actually was created by something else. And that's been the history the partnership that NASA has with its discoveries and the scientific community that will in essence, pressure test what we think we've found. So we're talking about perseverance. This was a mission sent to Mars under President Trump's first presidency, and a year ago we found a sample and it was again works blowing in places where there were rivers and where there were lakes, and much as on Earth, we think that that's where we'd see signs of ancient life on Mars. And so a year ago we thought we found what we believed to be signs of microbial life on the Mars surface, and so we put it out to our scientific friends to pressure test it, to analyze it, and go did we get this right? Do we think this is signs of ancient life on Mars? And after a year of review they've come back and they said, listen, we can't find another explanation. So this very well could be the clearest sign of life that we have ever found on Mars, which is incredibly exciting studies. The lead author a severed scientists Jell Hervitz from Stonybrook University. So is the combination of chemical compounds found in the bright Angel formation could have been a rich source of energy? Well, my craby alive. But he adds that just because they've identified all these compelling chemical signatures in the data doesn't necessarily mean they really had a potential bias signature. We really used every scientific instrument available to us on the payload to investigate these rocks and really try to tell or paint as complete a picture as we can of what these rocks are made of the environment they were deposited in and how the interesting features that we see in them might have formed. And what we saw in this rock were these layers of very fine grained, rusty red mudstone that had in them these incredible features, these things that we took to calling poppy seeds, which are the sort of dark black spots in the rock, and leopard spots, which are these kind of ring shaped features that have dark rims around them. These textual features told us that something really interesting had happened in these rocks. Some chemical reactions occurred at the time they were being deposited, and so we really wanted to understand what those reactions might have been. And one of the things we wanted to ask ourselves was is it possible that organic matter might have played some role in the generation of these textual features. So we turned to our organic chemical detector, the Sherlock instrument, and trained it on this rock. The data that we got back from the Sherlock instrument was fantastic. The set of spectra that are called Raman spec and there's a lot of information on these graphs, but the key thing to take note of is the fact that what we see in these spectra is something called the G band. The G band, for us, is a smoking gun indicator for the presence of organic matter in this mud. And we see that G band in the Chaiava Falls target, and we actually see it in a couple of the other locations that we interrogated around the bright angel formation, and this tells us that we had a rusty red mud that was deposited in the presence of organic matter. So the next question for us was was there some reaction occurring between the mud and the organic matter to give rise to those interesting poppy seed and leopard spot textures that we were seeing. So we turned to the other instrument out on the end of the rover's arm, called the pixel instrument. The chemistry of the surface of this rock rendered in three colors, red, green, and blue, and the mixing between colors is telling us something about where elements are present to get together. The mud itself, which shows up in red, is rich and iron. The things that are purple are rich in the elements iron and phosphorus, and that iron and phosphorus shows up in the poppy seeds and in the rims of those leopard spots, in the places where you can see sort of dull yellow to green tones. That's where iron and sulfur have been combined together in the cores of the leopard spots, and they have been combined into an iron and phosphorus bearing mineral that we think is vivianite, and an iron and sulfur bearing mineral that we think is a mineral called gregite. And what's exciting about these finds, this sort of combination of mud and organic matter that has reacted to produce these minerals and these textures, is that when we see features like this in sediment on Earth, these minerals are often the byproduct of microbial metabolisms that are consuming organic matter and making these minerals as a result of those reactions. But there are non biological ways to make these features that we cannot completely rule out on the basis of the data that we collected with our rover payload. So what we need to do from here is to continue to do additional research and laboratory settings here on Earth and ultimately bring the sample that we collected from this rock back home to Earth so that we can make the final determination for what process actually gave rise to these fantastic textures. Be Severan's project scientists Stadie Stack Mulgan from Nasus Jeff Propostion Lebar Trade in Pasaday into California says astrobologists claims, especially those related to the potential discovery of pastexs, that to rest your life requires extraordinary evidence. The discovery of a potential biosignature or a feature or signature that could be consistent with biological processes, but that requires further work and study to confirm a biological origin. Goose from years of hard work, dedication, and collaboration between three thousand scientists and engineers here at the je Propulsion Laboratory and our partner institutions around the country and internationally. Discovery like this comes from years of strategic planning and science analysis from both the Rover team as well as the Mars community as we went from the development of the Mars twenty twenty mission as a concept in response to the priorities of the planetary decatal survey, to the landing site selection, and now to the daily operations of the Rover that provide such a fantastic data set. The Presidents Rover landed in Jezero Crater in twenty twenty one, and this site was selected as a result of a multi year community effort because we decided that this site was truly the best place to accomplish the Mars twenty twenty mission goals of seeking signs of ancient life on Mars and putting together a collection of rocks for possible return to Earth in the future. Jesuro was selected because it's in a location amongst the most ancient terrains on Mars exposed some of the oldest rocks anywhere in the Solar System, and these really ancient rocks provide us a window into a period of time that's not particularly well represented on our own planet Earth, but into time when life was emergent on Earth and could have been on Mars as well. Jezro is also indisputably the site of an ancient lake, which we know because we have two river valleys entering into the crater and a river valley exiting the crater through which water flowed out of the crater. During the first four years of the mission, Perseverance explored three main geological terrains within the crater. The river landed on the crater floor, which was a sequence of igneous rocks, including lava flows and igneous cumulus that had a number of interactions with water and preserved probably micro environments that were likely habitable. The rover then transitioned to the western span, the sequence of sedimentary rocks, whose sediments were transported from ancient terrains out of the crater into the crater in a relatively long lived and state lake delta and river setting, the riverban transitioned to what we call the margin unit. This was a thick sequence of ibnious rocks that really are distinguished themselves by strong over these spectroscopic signals of the minerals olivine and carbonate. After the margin unit exploration, the river had a chance to traverse into the Retravalis, which is the main feeder river valley that once said the ancient lake that was present in Jezero this river valley more than three point five billion years ago. This valley would have been filled with rushing rivers carrying mud, sand, and gravel from outside the crater into the lake inside the crater. This kind of energetic setting was probably punctuated by periods of calm when water would have backed up, creating a relatively low energy lake environment where deposition by settling from suspension could have occurred. Eventually, though, this water dried up, the lakes and rivers dried up, and the bright Angel outcrop was revealed. And this outcrops for us a potential habitable environment that we can study and the rover can explore. On the surface of Mars. Today, Bright Angel is a distinct, light toned outcrop, and its current extent and relief has been exposed to us through billions of years of wind erosion and thermal cycling. The rover spent several months exploring this area, ultimately pushing to the edge the more an edge of the channel where the Bright Angel formation met the Margin unit and is here at the contact this edge of the river valley that the road explored a special target called Chiava Falls. The Java Falls rock and those around it show very thin layers. They're often red to tan in color, and they're very fine grain, so the sediment that makes them up is very very small. This couple with the fact that these rocks occur in a river setting, really points to a sedimentary origin here where we had deposition of these sediments in water. Here in this area we also have some coarser grained rocks. Sugget again suggests, and that we had a transition from those more energetic river environments two of the more calm lake environments. Well, every outcrop on Mars has an interesting story to tell. In order to really understand what makes this particular outcrop so special, we have to get our noses to the outcrop or in this case, the rovers arm up close and personal to take a look at all the details of these rocks. And while a biodic explanations for what's been discovered a brought angel alis likely given the papist findings, they can't be ruled out. That's a research Scientist Tory Hula says that any search for life, any tests for life, for that meta, would be extremely heavily scrutinized the full scientific community. We call this the podium test. What would it take for you personally to confidently stand up in front of an international audience. And make that claim? When you put it in that way, I think for a lot of scientists the bar is really high. So of course there would be obvious. Things, you know, a very clear signature of technology or a skeleton or something like that. But we think that a lot of the evidence that we might encounter first will be much more subtle, for example, chemical signs of life that have to be detected above a background of abiotic chemistry. And really what we see might depend a lot on where we look on Mars. For example, the long history of exploration there gives us a lot of context for what we might find, but we're potentially talking about samples that are billions of years old in those cases, and on Earth, those kinds of samples, the evidence of life is often degraded and difficult to detect. On the ocean worlds of our outer Solar system, So places like Jupiter's moon Europa, and Saturn's moon and Celadus, there's the tantalizing possibility of extant life, meaning life that's still alive. But potentially we're talking about exceedingly small amounts of samples that would have to be analyzed with a relatively limited amount of instrumentation that can be carried from Earth billions of miles away. And then for exoplanets, these are planets beyond our own Solar system. Really what we're looking for. There are very large magnitude signs of life that can be detectable through a telescope from many light years away, changes like the oxygenation of overs atmosphere or changes. In surface color. So any one of those things, if they rose to the suspicion of being evidence of life, would be really heavily scrutinized in a very sort of specific and custom way to that particular observation, But I think there are also some general principles that we can follow, and the first is just are we sure we're seeing what we think we're seeing. Many of these environments are not very well known to us, and so we need to convince ourselves that we're actually seeing a clear signal that represents what we think it represents. Carl Sagan once said life is the hypothesis of last resort, meaning that we ought to work hard for such a claim to rule out alternative possibilities. So what are those possibilities? One is contamination. The spacecraft and the instruments that we use to look for evidence of life are built in an environment Earth that is full of life, and so we need to convince ourselves that what we're seeing is not evidence of our own life, but evidence of indigenous life. If that's the case, we should ask should life of the type we're seeing live there? And finally, we need to ask is there any other way than life to make that thing? Any of the possible abiotic processes that we know and even the ones that we don't know, And as you can imagine, that will be quite a challenge. Once we have a piece of evidence in hand, that we really do think represents evidence of life. Now we can begin to develop hypotheses, for example, do we have separate independent lines of evidence to corroborate what we've seen and increase our confidence of life. Ultimately, all of this has to be looked at hard by the entire scientific community. In that sense, I think the really operative word in our question is we What does it take to say we found evidence of life? Because really the answer, I think depends on the full scientific community scrutinizing and skepticizing this observation to finally say that we scientists, we as a community, and we as humanity found life. That's NASA reset scientist doctor Torria Hiller. And this is space time still to come. An atmosphere disco on the frozen distant world of makey Make and a total lunar eclipse wews half the world. All that and more still the calm on space time. Indications of a methane gas atmosphere have been detected on the distant dwarf planet make Marke in the dark outer reaches of the Solar System. The findings reported in the Astrophysical Journal Letters and on the pre Press Physics website Archive dot org could indicate a tenuous atmosphere called an excess fee, or it could mean cry of volcanic activity on this distant frozen world. Market Make is one of the largest of the so called classical population of kuiperbird objects. It has a diameter of around one four hundred and thirty kilometers, making it about two thirds the size of Pluto, the largest known kuiperbird objec. The kuiperbuilt is a ring of frozen worlds, comets, and ici debris circling the Sun beyond the orbit of Neptune, the most distant known planet in our solar system, Marke. Marke has one known moon. The dwarf planet's extremely cold, with an average surface temperature of around minus two hundred and thirty degrees celsius, and its surface is covered with methane ethane possibly nitrogen isis, but it also shows signs of geothermal activity and so maybe capable of supporting active geology and maybe even harboring a subsurface ocean. The dwarf planet was first discovered back on March thirty first, twenty oh five, and was initially cataloged as twenty oh five f y nine. Later it was named make Marke after Creator God in the rape Nu and Mythology of Easter Island by the International Astronomical Union. The new findings of the methane xs fee were made using NASA's web Space telescope, and it makes Marke Mark only the second trans Neptunian object after Pluto where the press SSTs of gases has been confirmed. The Steadies lead author Silvia proto Papa from the Southwest Research Institute says the detection of methane in a gaseous form of Marke Marque makes this word even more fascinating. It shows that Marke Markee isn't an inactive remnant of the outer Solar System, but instead a dynamic body where methane ices are still evolving. The observed methane spectral emission it's being interpreted as solar excited fluorescence, in other words, the re emission of sunlight absorbed by methane molecules. Proto Papa says it could indicate a tenuous atmosphere in equilibrium with surface ices, similar to what Pluto has, or it could be a more transient activity such as cometary like sublimation or cryovolcanic plumes. Both scenarios are physically plausible, and both are consistent with the current data. Given the level of noise and limited spectral resolution in the measurements, Markee Marke has long been a source of scientific intrigue. Stellar occultation suggest that it lacked as stantial surface atmosphere, although a thin one couldn't be ruled out. Meanwhile, infrared data of Marke Marke, including the WEB measurements, inted at puzzling thermal anomalies and unusual characteristics of its methane ice, which raised the possibility of localized hotspots across its surface and potential outgassing. Future WEB observations using higher spectral resolution will help determine whether the methane arises from a thin bound atmosphere or from plume like outgassing. You alsors say their best models point to a surface pressure of only about ten picobars, that is around one hundred billion times below Earth's surface atmospheric pressure at sea level, and also a million times more tenuous than the atmosphere of Pluto. Now if this scenario is confirmed, Marke Marke would join a small handful of outer Solar System bodies where surface atmosphere exchanges are still active today. Predopapa says. Another possibility is that the methane's being released in plume like outbursts now. In this scenario, the model suggests that methane could be released at a rate of around a few hundred kilograms a second, and that's comparable with the vigorous water plumes seen on the Saturnian Iceman and Scyladus, and far greater than the faint vapors seen a series. Either way, the new findings off of fresh insights into the behavior of volatile rit surfaces across the distant transnt Tunian region. This is space time still to come, a total lunar eclipse wows half the world, and later in the science report, the latest check up of Australia's sexual health. All that and more still to come on space time. Well, if you're in parts of Australia, eure of Africa or Asia, you may be lucky enough to experience a front row seat or what was The spectacular total lunar eclipse event, which was the second this year, saw Earth's shadow obscure the full Moon, turning it blood red. The entire spectacle evolved over some five hours, starting with a first dusky spite of the Moon, and totality lasting a full hour and twenty two minutes. The event was a prelude to a partial solar eclipse which will be visible this week from New Zealand, a sliver of the Australian Pacific coast, numerous South Pacific islands, and parts of Antarctica. So exactly what is a total lunar eclipse and how does it happen? Well, it can only occur when the Sun, Earth, and full Moon a line. During this event, the Moon passes completely through the Earth's dark shadow known as the umbra. Now, even though Earth completely blocks sunlight from directly reaching the surface of the Moon, the Moon is still visible. It gradually gets darker and then takes on a rusty or blood red color as light from the Sun refracts through Earth's atmosphere and undergoes rarely scattering, leaving only the longer red wavelengths of light. Think of it as all the earth sunrises and sunset's happening at once and then indirectly being reflected onto the lunar surface. Now, total lunar eclipse can also look orange, yellow, or even brown in color, depending on how different types of dust, particles, and clouds in Earth's atmosphere allow different wavelengths of light to reach the lunar surface. Partial lunar eclipses happen when the only parts of the Moon's surface is obscured by the Earth umbra. Then there are penumberal lunar eclipses. They happen when the Moon only travels through the faint penumberl or outer portion of Earth's shadow. Now, a lunar eclipse is different from solar eclipses, which happen when the Moon's orbit lines up so that it passes directly between the Earth and the Sun. They can only happen on New Moon. Whatever the event, it's a spectacular display of orbital mechanics at work. This is space time, and time that to. Take a brief look at some of the other stories making news and science this week with the Science Report, A new study suggests that a quarter of recent heat waves would have been virtually impossible without man made climate change. The findings, reported in the journal Nature, are based on two entyd and thirteen heat wave events between the year two thousand and twenty twenty three. Researchers assessing the impact of climate change examined data from one hundred and eighty of the biggest carbon emitters. These are industries or processes which contributed some fifty percent of the total increase in heat wave intensity or The latest check up of Australia's sexual health has been released and it's found that over the past decade, Syphalis diagnoses in Australia if almost doubled, gone area is more than tripled, and chlamydia diagnoses remain high. But there is some good news. It seems HIV AIDS infection has declined. The new National Civilance data findings were presented at the Australasian HIV and AIDS Conference in Adelaide by the Kirby Institute at the University of New South Wales. However, the study is incomplete. Researchers say they found significant gaps in sexual health testing among the Australian population, so we're really not getting a full picture of what's happening everywhere. The Australian Navy will spend one point seven billion dollars on a new squadron of twelve autonomous unmanned ghost Shark submarines. The new attack drones will start entering service next year undertaking intelligence gathering, surveillance, reconnaissance, and strike operations. The Department of Defense says the new Ghost Shark xlauvs will provide stealthy long range Kindestine under sea warf air capabilities. The six mint long vessels are designed to be launched either from onshore facilities or from motherships at sea across the world. Honest journalists have died putting truth to power, yet corrupt journalists proudly present that by unbalanced and dishonest reports as factual news. News reporting should be based purely on the facts, without any editorializing or personal opinions. Those who include their own views in what should be as straightforward news story are corrupt and have no credibility. There are many once great news organizations that are now little more than sheltered workshops full of arrogant virtue signaling self important liars pushing their opinions not as the editorials they should be, but as news. And that's dishonest and corrupt. But it's tim minium from Austrian skeptics points out. Then there are those journalists who just leave you stunned with air low level of understanding of what the very craft of journalism is all about There. Are times when you as a journalist and you see some stories in there that you just make you despair. Right of journalistic effort and research should not be to take someone's press release and reprinted a fact. But it's a story that appeared recently in a restrained newspaper online certainly about exorcist. This story is just a promo peace the journalists allowing her to just say anything at all, and there's no questioning, there's no research, there's no critical thinking applied to this story at all, including down to the fact that over the last twenty years of her career she's cleared over five thousand homes. So I'll go spirits now that memory is actually sort of looks like one exorcism. They every working day, which must make it pretty busy. Although I actually got in touch with a journalist and said, how does she do that? He said, oh, she's recently cut her down to two per week, which makes it in the first half of the career, how was a lot busier to actually do all these exorcistes. I think it's one of those figures. To me, it sounds like it's made up, But who knows. Maybe she can got a list, but she's treated billionaires and others. Does she run around the play shuring the power of Christ commands you? What does she do? We throw it a water around and there It makes it sort of sound good. The trouble is there's no evidence for what she says. It's just her to say so. And I find this more of a concern, not that these exorcists exist. They do, whether their official Catholic Church exorcist or whether they're just professional to go around during this sort of stuff. Disappointing going to happen. It's just is disappointing when you see a newspaper which is basically a press release, a puff piece for a particular practitioner, which gives her a lot of publicity, cub, he gives us some credibility if the pie's in a decent paper. How many times have you and I spoken about the quality of journalism these days? Yeah, I know what you're thinking, and I will say the same thing. When you've seen journalistic practices, you see what's based on most journalists, you would hope, and decent people trying to do with decent stories, they're perhaps under pretty severe restrictions these days. Is that I have to do more stuff with fewer people. But when you see this sort of thing, okay, full space. If if someone just sends you a lot of blurb and you just do a cheap and cheerful interview with someone and then you publish it, You've just written up your one thousand words requirements for a story and no one seems to care that it may not be true. But just for a matter of interest, what this exercis says, how to keep spirits out of your home? You burn essential oils. I've heard people who sell the central oils not know what they mean by es central oil. I think it's necessary, it's essences, not essential, not necessary. Play calm music and what the music is, and know what calm is to you. Barry mellow rather than deep purple. Yep, you have to open your windows. I've got no idea what the different type of the winds that are blown a spirit away. We'll get rid of some of the spirits anyway, and. D class regularly. Most of the sounds like good advice, just to keep the house cleans it, ghosts or not. The story is silly, but it's long, and it's disappointing that appears to recognize newspaper. That's Timendum from Ustrilian Skeptics, and that's the show for now. Space Time is available every Monday, Wednesday and Friday through Apple Podcasts, iTunes, Stitcher, Google Podcasts, Poker Casts, Spotify, a cast, Amazon Music, Bytes dot com, SoundCloud, YouTube, your favorite podcast download provider, and from space Time with Stuart Gary dot com. Space Time's also broadcast through the National Science fan on Science Own Radio and on both iHeartRadio and tune in Radio. And you can help to support our show by visiting the Spacetime Store for a range of promotional merchandising goodies, or by becoming a Spacetime Patron, which gives you access to triple episode commercial free versions of the show, as well as lots of bonnus audio content which doesn't go to weir, access to our exclusive Facebook group, and other rewards. Just go to space Time with Stewart Gary dot com for full details. You've been listening to Spacetime with Stuart Gary. This has been another quality podcast production from bytes dot com.