Science Friday - Lack Of Black Physicists, Solar Outages, Martian Meteorites, What Is A Butt. March 4, 2022, Part 2

Episode Date: March 4, 2022

Where Are The Black Physicists? Black scientists make up less than one percent of physics PhDs in the U.S. And since 1999, most physics departments in the country have failed to graduate more than one or two Black undergraduates. Furthermore, the share of Black students in physics is declining: If the number receiving a bachelor’s degree in physics had kept pace with the rising popularity of the major, there would be 350 Black physicists graduating every year. Instead, in 2020, that number was 262. But why is this number so small? A comprehensive investigative series in Science Magazine this week examines those statistics, the academic climate of physics departments, and how academia may be limiting the achievement of Black students. The series also highlights some success stories about proposed solutions, with mixed results. But why is physics a uniquely white, male discipline—and how can institutions make the climate more friendly to students from marginalized backgrounds? Ira talks to Apriel Hodari, one of 150 Black women to receive a PhD in physics in the U.S., who now researches the culture of higher education in STEM fields.   Why The Equinox Can Make Your Credit Card Fail Twice a year, people listening to signals from satellites in geostationary orbit face a problem known as a solar outage, a solar transit, or sun fade. Around the spring equinox, the Sun approaches the equator from the south, as the north gets ready for spring. In the fall, near the autumnal equinox, the Sun appears to move back below the equator. During these times, it comes into the view of Earthbound satellite dishes directed at geostationary satellites positioned some 22,000 miles above the equator. When a ground receiver, the satellite it’s looking at, and the Sun all line up, the radiation from the Sun can temporarily overwhelm the satellite receiver. Think of it like when you’re driving on a westbound road close to sunset, and you’re staring straight into the setting sun—it gets hard to read the road signs. The effect is temporary: a maximum of 12 minutes at any given location for several days in a row. But it can affect everything from a satellite TV dish to credit card processing at your local gas station—even public radio stations receiving live programming over the satellite network. SciFri’s Charles Bergquist talks with Chris DeBoy, who teaches a course in satellite communications at the Johns Hopkins University (and is also the RF communications lead for the New Horizons Mission to Pluto, and the Space Engineering Branch Manager at the Johns Hopkins Applied Physics Laboratory), about the advantages and disadvantages of geostationary satellites, and what can be done to minimize the impact of solar outages. They are joined by MaryJane Peters, technical operations chief at KAZU in Monterey, California, who describes the effect the seasonal outages have on station operations. Can Meteorites On Earth Point To Ancient Life On Mars? In 1996, the late astrobiologist David McKay and his team published a paper arguing that a four-pound rock from Mars, called Allan Hills 84001 (found in Antarctica), showed evidence of ancient microbial life on the planet Mars. The team pointed to several mineral structures, including tiny beads of magnetite, as well as shapes that might be fossilized bacteria. This hypothesis ignited a storm of controversy and a flurry of research that contradicted the team’s theory. But decades later, ALH 84001, like the other meteorites that have been linked to the Red Planet, remains an important insight into Martian geology and the formation of organic molecules in the absence of biological processes. Producer Christie Taylor talks to astrobiologist Andrew Steele, who has been studying ALH 84001 and other meteorites for decades. He discusses the process of probing meteorites for data, the difficulty of studying rocks without their original contexts, and how new samples from the Perseverance rover could change everything. Plus, how the original controversy over ALH 84001 changed the trajectory of planetary science.   From Zero To 100 Butts: The Wild World Of Invertebrate Behinds Recently, the staff of Science Friday came across a tweet that caught our attention, sent out by researcher Dr. Maureen Berg.   Turns out, it was a call to source comic ideas for Invertebrate Butt Week, a celebration of—you guessed it—the butts of invertebrates. “Invertebrates really get the short end of the stick,” says Rosemary Mosco, the creator of the comic series Bird And Moon and #InverteButtWeek organizer. “People are not as excited about them as, say, a majestic whale or a beautiful bird. And I love my birds, but [invertebrates have] such an incredible diversity. So, butts are sort of a cheeky way to access some of that amazing diversity and celebrate it.”   Rosemary and other scientists and illustrators teamed up to create #InverteButtWeek, a celebration of the behinds of the backbone-less. “It’s a chance for some people who do science communication to do the silliest thing that they can possibly think of,” says Dr. Ainsley Seago, curator of invertebrate zoology at the Carnegie Museum of Natural History.   Science Friday’s Daniel Peterschmidt talks to the organizers of #InverteButtWeek about how it came together, their favorite invertebrate butt facts (like how sea cucumbers have anal teeth), and how you can participate in the celebration.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. A bit later in the hour, we'll talk about what media writes from Mars can and can't tell us about the red planet. But first, why are there so few black physicists? It's well known that science, technology, engineering, and math, STEM, has been grappling for decades about the paucity of people of color in science. Reporter Jeffrey Mervis at Science magazine surveyed the field and found the problem to be the worst in a particular area, physics. Black scientists make up less than one percent of physics PhDs. The wider picture is not much better. 30 percent of physics department in the country have not graduated a single black student since 1999. Another 30 percent have only graduated one or two. The irony is there are actually

more undergraduates getting physics degrees these days. And if the number of black students getting a physics degree had kept pace with the rising popularity of the major, there would be 350 black physicists graduating every year. Instead, in 2020, that number was 262. Even so, many of those physicists are graduating from historically black colleges and universities. So why are physics departments so bad at graduating black students? And what can be done differently to increase that number? Joining me is one physicist who studies this problem, Dr. April Haudari, a physicist turned social scientist and principal investigator for Eureka Scientific. She joins us from Washington, D.C. Welcome to Science Friday. Thanks for having me. Nice to have you. You know, the articles I just mentioned

talks about your investigations into the culture of STEM education and physics departments, and one of your recent studies asked white faculty how they perceive this bias against black students and scientists. What was the result? What happened? Well, we interviewed or we hired white male researchers to interview white men, actually. And what we learned is they have some very interesting ideas about race and gender, often problematic ideas. So the important thing to say is that these are all men who volunteered to talk about race and gender. You can assume they're the more liberal ones within the field who volunteered to have this conversation. Yet they don't know a whole lot about it. They tend to know a lot more about gender than race. They don't have a

deep understanding of what discrimination is and what it looks like, for example. But even if they tell stories of women close to them who've experienced discrimination, when we ask them more broadly, is discrimination or sexism happening in physics? Across the board, they say no, they've never seen it. And so for a lot of them, the big takeaway was, well, even if this is happening across physics, it's not happening here, it's not in this department, it's not on this campus, it's not in this region of the country, which then absolves them from the responsibility for doing anything because it's outside of their sphere of control.

How many other departments around the country do you think is happening, and they don't know it either? Most, unfortunately. And as the story in science this week notes, you are one of 150 black women to have received a degree in physics overall. Yes, in U.S. history. And total U.S. history. Why is that number so small? I think lots of reasons. I know that there are people who are interested in the discipline, but similar to most people, as a working-class,

city kid. I grew up in Chicago. I was encouraged to consider more practical fields. In fact, my undergraduate degree is electrical engineering. So most people don't have a sense of what physicists do. Another big factor is, as compared to a field like engineering, where you're considered a professional at the bachelor's level, you really aren't considered a physicist unless you have a PhD. So the bar is really quite high. You know, as my dad used to say, well, I appreciate all these fancy degrees. You but you still can't fix my TV. Like it doesn't translate to everyday people. Most people think of big bombs or some esoteric thing,

like I'm going to sit around and think about an atom all day, and why would you do that? So in a lot of ways, it's painted as something that's not practical that people don't understand. Or one of the elements of culture is physicists, really, we believe we're the smartest people on the planet. And what that translates to when you're communicating to others is you have to have some overwhelmingly genius level innate ability to fit into our club.

Yeah. I remember when I was studying engineering many, many years ago, there was only one female engineering student in the whole class. We've talked about the struggles of women specifically trying to participate in science. So what happens when someone has multiple identities that are marginalized like black women? Right, but it's interesting, though, that there are other things. Like, I've studied women of color specifically and a lot of black women for over two decades. And I specifically study women who are successful in these fields where they are vastly underrepresented. And what you find is these women are not only in love with their science, but they have been their whole lives. I fell in love with math at seven.

They have extremely high amounts of internal motivation. But there's also a not thoroughly studied phenomenon that for whatever is in engineering, a lot of black women go into electrical engineering. No one knows why, but it seems to attract a lot of black women. So it's not that there's not interest or even talent. The cultures of these disciplines are not encouraging or supportive generally. I was pretty lucky. I went to undergrad at Purdue in a context where the percentage of women was a bit above the national average. And the support structures were amazing, both for black engineering students and women engineering students. But most students are not educated in that kind of context, especially outside the HBCUs. That is close to what I heard from Dr. David Satcher, you know, a former Surgeon General now at Moorehouse School of Medicine,

health care issues among underserved black communities. And he said that in changing the system, there was a need to encourage and grow more leadership among new black physicians. Do you think that is true in science leadership and particularly in physics? I think leadership is needed, but I think that people can be leaders who have lots of different identities. For example, my colleague Angela Johnson and I have studied. institutions in the departments in which women of color thrive. And they are uniformly, are almost all the ones we studied, predominantly white institutions, predominantly white, predominantly male faculty. The difference is that they really personally and

collectively invest in their students and in all of their students. They see all of their students as precious and worth their time and energy. They make it their job to, ensure the students learn. They back that up with policy. They provide space for students to collaborate. They provide all kinds of support. They innovate both in their learning about people's experience across boundaries of identity. And students tell us, their students tell us, they interrupt sexism, racism, all kinds of things in the moment. Even as one student put it, even if he's uncomfortable, geeky physicist and he looks like this is the last thing he wants to do, the fact that he does it anyway means I can trust him. So I think there are people who do do this and that it's not only

the job of the few faculty of color or women of color faculty, but it's everybody's job to invest in these students. And you say that one of the problems with physics education is how they perceive their students, this thing called the deficit model? Yeah, it really is. If you've ever heard faculty members or teachers of any kind say things like, oh, we just got a bad batch of students this year. That's the deficit model. And so what I know from the work I've done in places where everybody thrives is those faculty think it's their job to do everything they can to ensure all their students thrive. So they're not thinking differently about the talent of any of their students, especially their students of color or women. They really are focused on how do I do a better job,

ensuring that all of my students can be successful, learn deeply, and move into successful careers after they leave. Is there any policy or incentive that we can give these professors or universities to think more along those lines? Certainly. I mean, we could take teaching and scholarship around learning and DEI issues more seriously. We can treat this with the same level of professionalism. We treat our science. That's a rarity.

We certainly can incentivize it. For example, the UK is not perfect, but included in the way they evaluate the quality of a school is how do their graduates fare after they leave? What do they earn? How many of them get jobs? Things like that. In the U.S., we rate schools by how hard they are to get into, essentially how many people they reject.

That doesn't measure what happens to them as they learn or after they leave. Why are other people of color having more success than black physics majors to graduate? I think unlike part of the belief of what happened in physics culture is what Sharon Trowee calls the culture of no culture, where physicists believe that because our science is not about objects that are raised or gendered, that we can ignore societal influence. But the people who populate people are just physics. And in the U.S., those people live in a racist, sexist, classes, culture, national culture. So those things translate. And as I heard early in my career, one leader in physics say, well, part of the problem is we look at women and minorities and we don't see diamonds in the rough that can be cleaned and cut and polished and will grow up to look like us. And that's what I mean when I say those people who do this well do see them as equally deserving as potentially diamonds in the rough or as my colleague Beth Hoffnagle and I suggested in a response to these comments that perhaps those physics leaders who don't see them that way should learn to appreciate other precious stems.

there are rubies and sapphires and other things that can be equally as precious. Well, I don't think I could end the conversation on a better note than that. I want to thank you for taking time to be with us today. Thank you. Dr. Apriol Hodari, physicist, social scientist, and principal investigator for Eureka Scientific. You can find a link to Science Magazine's full series on our website, Science Friday.com slash physics. After the break, why does springtime mean satellite outages?

is. We'll take a look. This is Science Friday. I'm Ira Flato. This week marked the start of meteorological spring. But if you ask an astronomer, the true start of spring, is it until the equinox on the 20th, and we baseball fans mark spring training, hopefully this year, as our spring marker. Here's Cyphrise Charles Berquist with another right of spring.

Ah, spring. Flowers poking up, trees starting to bud, And satellite receivers having problems. Interference, so it'll be some noise like that, and then eventually it'll completely... That's Mary Jane Peters, technical operations chief at KAZU in Monterey, California. It would vary anywhere. It was pretty close to right on time. I would be running the... Attention, KASU listeners. We are experiencing a solar outage. It's a phenomenon that affects people listening to signals from satellites in geostationary orbit.

It's called a solar outage, a solar transit, or sun fade, and it happens without fail twice a year, right around now, in fact. During what we call the spring and fall equinoxes, the sun approaches the equator from the south as the north gets ready for spring, and then in the fall as well, the sun is dropping down from the north into the equator and below as we head to winter in the northern hemisphere. Chris DeBois teaches a course in satellite communications at the Johns Hopkins U.S. University. He's also the RF communications lead for the New Horizons Mission to Pluto and the space engineering branch manager at the Johns Hopkins Applied Physics Laboratory. But at this time, viewed from the Earth, the satellite out in geostationary orbit, right behind it is the sun. And the sun is not just emitting energy in the visible range. It also emits energy in microwave frequencies. And microwave frequencies are used by communication satellites. He explained why

these geostationary satellites are so attractive? If you go out about 22,000 miles around the Earth and you put the satellite's orbit in the equator, it turns out that the satellite is orbiting the Earth at the same rotation rate that the Earth is spinning. And so the satellite in this special orbit we call the geostationary orbit stays fixed in the sky from wherever you are on the Earth's surface, which makes it great for lots of things. For one, from that distance a satellite can see one entire half of the Earth at a time. For another, it means that a listener on the ground won't have to constantly re-ame their satellite dish to follow the satellite. The geostationary belt is some of the most

valuable real estate in space because each satellite is assigned a longitude, basically, in that belt, and every longitude is occupied with companies wanting to provide communication services to people here on Earth. If you're listening to a live national broadcast on your public radio station, there's a good chance it's been delivered to the station from a geostate stationery satellite called Galaxy 16, positioned at 99 degrees west longitude. But during these twice a year outages, if you draw a line directly from the station's satellite dish to Galaxy 16, the sun shows up right behind it. Think of it like when you're turning onto a westbound road close to sunset and you're staring straight into the setting sun.

It gets hard to read the road signs. The ground station are the eyes of the satellite operators looking up the satellites with very powerful binoculars, so to speak. And you can imagine if the sun gets in your eyes, well, you don't like it. The sun's noise power can be hundreds of times more than the background noise power in a typical satellite link. While the sun is behind or near that satellite, it's going to swamp the signal and you and you basically lose contact for that time.

Mercifully, the sun, although is relatively small in space, it's about a half a degree in diameter. And it moves one diameter, about the half degree every two minutes or so. So the maximum amount of time for these outages is limited to about 12 minutes and sometimes less. Any given location on Earth will have to deal with these momentary outages for a stretch of a few days at a time. And it's not just public radio stations. These outages affect any kind of satellite receiver looking at a geostationary satellite, from satellite TV to phone communications with distant areas.

There's a surprising number of industries that use satellite on a regular basis, government services, military services, and industry commercial service. You go to the gas station, and a lot of the transactions are beamed up through very small aperture terminals to geostationary satellites, things you may not think about, but SATCOM, satellite communications touches us multiple times every day. So how do you deal with the problem? Well, we can't turn off the sun. So that will be a bad thing for everybody.

A couple of things that one can do, if there are additional satellites in the neighboring region that your satellite operator has access to, you can shift your signals to that satellite in a neighboring slot in a geostationary belt. And while your prime satellite is in a sun outage, you can get your service from that other satellite and then flip it back. In today's world, terrestrial return, so getting data off of the internet or through some specialized feed during these times is a good backup. Mary Jane Peters says at her station, she sees a couple of work If a station's playing local programming or something that's pre-recorded, you'd never hear a problem. New receivers at stations can start playing an internet stream in the event of an outage.

So you might hear a little glitch, your clocks might seem off, or you might not even notice. Stations can also download episodes of a show in advance or have some music standing by to cover any uncomfortable silence. And in the public radio world, there's always another workaround. or not, and ask for... Another right of spring. For Science Friday, I'm Charles Berkwist. This is Science Friday. I'm Ira Flato.

About 25 years ago, a little piece of Mars caused a big commotion. A potato-sized meteorite from Mars, known as Allen Hills 8401, was picked off the ice in Antarctica in 1984. Lots of Martian meteorites are found out Earth. What made this one different was that in 1996, the late Asthmaeus, the late Asthmae astrobiologist David McKay decided this four billion-year-old piece of Mars showed evidence that the red planet had once contained life. Mineral traces and structures on the rock, McKay thought, could only have been created biologically. You can still read the press release for when that

research was published. Meteorite yields evidence of primitive life on Mars. It's up there in our website, Science Friday.com slash Mars Rock. We talked about the Allen Hills media right in 1997, after a flurry of research began to challenge McKay's findings. Here's planetary geologist Ed Scott. We've been focusing on the carbonate minerals that were alleged to contain the signs of life. Our group is convinced that the carbonate minerals must have formed at high temperatures. They didn't form over long periods of time from water, which was oozing through the fractures in the rock. we think they carbonates formed at very high temperatures, well over 1,200 degrees of Celsius.

We think they formed very rapidly in an impact. Further research in the decades since has ruled out many of McKay's conclusions, but the meteorite is still an important part of research into ancient Mars and conditions for possibly living there. Producer Christy Taylor recently revisited the storied past of the Allen Hills Meteorate for the sci-fright book club. Welcome back, Christy. there, Ira. Nice to have you back. And of course, we are reading the Sirens of Mars by planetary scientist Sarah Stewart Johnson this month, all about the search for life on Mars, which includes

the bits of Mars that have landed on this planet. I take it Sarah talks about this media right in the book, right? She does. It gets an entire chapter, which feels very fitting given its importance in our understanding of Mars. Sounds great. Take it away, Christy. Sure. So I talked to astrobiologist Andrew Steele. He's been studying meteorites like Alan Hills. for decades. He actually worked with David McKay starting shortly after that first very controversial publication. And he also works on both the Curiosity and Perseverance Rover Missions. So I started by asking him to just describe this piece of rock from Mars. And as you said, it is indeed potato-sized. It looks like any other rock. It's very fine-grained inside. It means that the crystals are really small.

and it has in some places this kind of reddish tinge and that reddish tinge is these small rosettes of carbonate. On earth, such things can be made by life and that really drew the eye in of Dave McKay and his team into really looking at those. So it really looks quite nondescript. It's quite heavy. It's blackened on the outside

because of its journey through the atmosphere as it melts. But apart from that, it's really quite a little. nondescript rock. It's small and yet so important in our understanding of the universe now. Why did David McKay think that this meteorite contained evidence of life? At the time Dave McKay began the studies on Alan Hills 840O1. We had a range of measurements on early Earth samples, for instance, that indicated that life was on this planet around about 3.6 billion. And the initial dating of this Martian meteorite Alan Hill 8401 showed it was an equivalent age of when life had started on Earth, and it was the equivalent

age of that rock on Mars. And so their initial analysis of the rock showed the presence of organic molecules in polycyclic aromatic hydrocarbons. It also showed a kind of disequilibrium texture that life tends to like to do. It kind of makes minerals in strange places. In these carbonate global also there was these small magnetite grains that certain species of bacteria like to use on Earth, magnetotactic bacteria. And all in all, there were four to five lines of evidence, all pointing towards a possible biogenic explanation. One of the lines of evidence that you just described was just he thought he saw something that might be fossilized bacteria. What did that look like? as you go into the microbial world, the shapes that the microbial world adopt at the simplest

level are pretty uniform. They're either small circles, small spheres, small rod shapes, and on the rock themselves, they found evidence of these small shapes around about the size range, a bit smaller, actually, than earth-bound bacteria. And at the time, again, in ancient rocks on earth, it was the search for fossils, which was very much part of the debate at that time. So, and they used technology at that time, which was cutting edge to look at Allen Hills 8401 in a way that many of the rocks hadn't been looked at like that before.

And so they found these fabrics and features that really pointed them towards it being evidence of fossil life. And then, of course, others disagreed. What was their reasoning and what did their research show to sort of counter that postulation? Well, there was several things. One was it could be an artifact of sample preparation for these kinds of analyses, which is where my initial work came in, showing that potentially wasn't.

There was also that these features are on the small side of what we know about life on air. And so that kind of jump started an effort amongst the scientific community to delineate what the smallest form of life could be on this planet, at the time, ultra-micro-microbacteria or nanobacterial features that were being seen, and were highly contentious then and still to some extent are contentious today. So the lower size limit for life, how small could an organism be? How could you pack all this cellular material into something so small? You've said that we couldn't even find earth life that was contaminating this meteor right until you looked at it and imaged it.

Is it really that hard to find bacteria on a piece of rock? Well, the thing is, I think the scale of the problem is really interesting. Yes, we did find contamination. Dave McKay actually brought it to me to classify because he had found it and said, this is unusual, what is it? And so we classified it as a bacteria from Antarctica. And at the time, the extent of life on Earth, wasn't really known as it is now. And certainly the extent of microbial life in Antarctica

wasn't really appreciated as it is now. We thought Antarctica was sterile. Pretty much. Pretty much. You know, this analysis showed that this was probably a type of bacteria called an actinomycite and was growing on the rock. And at the time, a lot of techniques said there is no life in this rock. But there was, there was, there was earth life. And that struck me as being, can't see the wood for the trees. But if you think about trying to find a single microbe or a small group of microbes on a rock, you have to understand the scale of that. So you can literally fit 100 bacteria on the pointy bit of a pin. And so finding those within a rock is not easy. And the amount of carbon, for instance, in a single bacteria

is 0.1 with 13 knots, right? It's vanishingly small, 10 to the minus 13 of a gram of carbon. So detecting microbial cells at that level is not easy. Just a quick reminder that I'm Christy Taylor and this is Science Friday from WNYC Studios. Talking to Dr. Andrew Steele about meteorites from Mars and how we can study them. What does the biology of microscopic life tell us about how to look for it in samples of rock? That's a really interesting question. Life has an ability to be able to kind of concentrate the ingredients it needs,

either to make itself or to eat or what it excretes. And what we found in meteorites left over from the building of our solar system, we see that a lot of organic chemistry goes on in those rocks. thousands and thousands of compounds are made, but life doesn't choose all of them. It only chooses a subset of those. So if you look at that, what you need to do is look for concentrations of these letters above and beyond what organic chemistry would do in these rocks. And I think the biggest lesson for me, certainly and others in the community,

was that the scale of that search is one where you have to be, ridiculously sensitive with the instruments that you're making the measurements with, and ridiculously careful that during all of that process and during the time that meteorite has been on Earth, that Earth life doesn't interfere with those measurements. Well, I have a question sort of on that vein. Someone in Antarctica finds a new meteorite. They send it to you. What kinds of instruments do you then submit your samples to? How are we actually probing what's in there? Well, I think it's like with any sample, if you're an earth geologist looking at earth life, you would first go to the place where you picked it up.

So you would know the context of the sample. I'm picking it up from this rock face and this rock face looks like a sedimentary rock or an igneous rock. And the first thing you do is, obviously, as you photograph it, you just look at it, describe it, its context, what its mineralogy is, what kind of rock is it. And then you can do a couple of different things, and I tend to do both. One is to look at fresh fracture surfaces where you just chip little bits off and put them under a light microscope at first. So you start at low magnification and slowly get increased the magnification that you're looking at the rocks so that you can look with increasing resolution and increasing detail at the mineralogy of the rock. Or you can slice it into really thin slices and look through the rock. And then at that point in time, I use a spectroscopy technique called Raman spectroscopy.

And what that allows me to do is look within the rock. We need to take a break. We'll be back with more on Mars, meteorites, and the hunt for signs of life in a moment. Stay with us. This is Science Friday. I'm Iroflato. In case you're just joining us, Cy-Frize Christy Taylor is talking to astrobiologist Andrew Steele about looking for signs of life in meteorites and ancient rocks.

All right. So we're walking through looking at a new meteorite, and you've just taken a deep look at the mineral structure. But what about all those organic molecules? What we found was in several of the meteorites, including Allen Hills, is a signal of a kind of complex organic material. It has several different names on Earth. If it's from life, it's called kerrigin.

If it's in bacteria, it's called insoluble organic material. I tend to call it macromolecular material or refractory material. Because it's trapped within the mineral, it's not seen too much of terrestrial conditions around it. And what you can do then is very minutely cut little slivers of that material out from the sample and put them on instruments that then go down to the point where you're basically imaging or analyzing individual mineral lattice. This is all the way down at almost the atomic level. Oh, wow. And at that point, you can see and use different techniques

to kind of interrogate more the nature of the organic material in there or the minerals in there and get the relationship between the organic material and the surrounding mineral matrix. Is this something that looks like, say, a bacteria sat on a mineral surface or a bacteria that's kind of edged its way into a mineral surface or does this look like just a puddle of carbon with no real structure to it? You start to pick up how the actual carbon relates to the mineral matrices around it. And from that, you gain a lot of information as well morphologically,

and then we can use these really high-resolution techniques, that many of which weren't available back in 96, certainly not in the same resolution we are now, and really start to unpick the nature of the organic, material there. You know, you've mentioned all these techniques that weren't available in 1996. You know, if we haven't found evidence of life in any of these meteorites, even with all these techniques, what have we learned about Mars as a result of looking at them? Well, we do know between this and the work on Alan Hills 8401 and the descent meteorite

and curiosity and now perseverance, we're finding that Mars had quite an active organic chemical cycle and that Mars does do its own organic chemistry, which has major implications for early Earth or Enceladus or Europa and how organic chemistry could be expected to produce the building blocks of life on those bodies and on Mars. My studies don't necessarily negate that there is Martian life in these meteorites, right? It's what I look at is this complex organic material. Basically, if I want to find life, I assume there is no life and try and disprove that hypothesis. And I can't disprove that the non-life processes make this material. So the absence of evidence isn't the evidence of absence. Bingo. But it's a stepwise,

it's a stepwise journey. And some people, I rightfully so, if you think about it, it's more difficult to prove a negative than a positive, right? But what this has done is what the McKay group did and effectively over the last 25 years have enabled the community to start thinking about this. They've enabled the whole debate, enabled a series of missions to Mars, the like of which our species had never undertaken before. It has enabled us to attack those problems and really think about those problems and develop instruments and protocols and procedures to understand how to find life on another planet. And the spinoffs of that in the Astrobiology Institute and the NASA funding agency has spun out many programs to try and really unpick how to find life elsewhere.

But that has led to a greater understanding of life on our own planet and how life could have possibly formed here. It caused a real revolution in our understanding of where life could be in our own solar system. And I think the greatest legacy of this paper is. in the search that we're still on. And Dave and his team should be commended for having the courage to put that hypothesis out. Well, and I think my last question then is if you had to choose between more Martian meteorites or better instruments, what do you think the most important thing would be? We have over 200, I think, Martian meteorites now. And I think I would like to see all of the analysis we're doing on Marshall meteorites now, one of the

spinoffs of doing that analysis is understanding the analysis chain that you have to go through on return samples, understanding the measurements that we have to make and how we make them and how we begin to make them is the most important part of that. And I think for me, if you in that question assume that we are going to bring back samples from Mars, I think the way in which we look at those samples, the way in which we analyze them, the techniques we use need to be not just developed, but the lessons learned from Allen Hills,

the lessons learned from Ticin and the other Martians meteorites, need to be put in practice to analyze the return samples. And that's not an easy thing to do if you think about the challenges associated with bringing a sample from another planet, planetary protection,

where you store the sample, keeping it clean how you analyze it. Those things, it's a really big unknown at the moment. And NASA is working on this. So as a European Space Agency, the Japanese Space Agency, all trying to figure out how best to do this in a way that keeps the planet safe and also keeps the sample safe and allows these techniques. And, you know, future generations are going to say,

I'd like to do this analysis, this new instruments. I think it will do this. And how you ensure that legacy on. the return samples with those instruments, I think is key. And this debate started really with the ALH and meteorite and it's still ongoing. And I think it's, again, one of the legacies of this meteorite and the team's analysis on this meteorite has been to really illustrate and illuminate the path forward in analyzing the samples as they come back from Mars.

Well, good luck in the meantime. Thank you so much, Dr. Steele. It's been a real pleasure. very much for having me on. Andrew Steele is an astrobiologist at the Carnegie Institute of Science. He works on the Perseverance and Curiosity Mars Rovers. Fascinating stuff. And Christy, we're reading the Sirens of Mars all month if folks want to continue on this

Martian Book Club journey. Step one, Ira is always to go to our website, ScienceFriday.com slash book club. But this week we have an extra special ask for our audience. We want to know what you think life on Mars looked like. if you think it happened at all. Carl Sagan famously thought giant turtles could have roamed the planet. Andrew Steele was just talking about microscopic life, but what do you think? You can contact us a few ways.

You can send us a voice memo with the SciFri Vox Pop app wherever you get your apps. That's the SciFri Vox Pop app. And we have a phone number you can call it any time you want. That number is 646-76-67-6532. Again, 646-6-767-6532. leave us a voicemail and tell us about Martians. And again, for everything else we're up to this month, check out ScienceFriiday.com slash book club. I love that fact toy that Carl Sagan thought there were turtles. It's amazing, right? Thanks so much, Christy. Thank you.

This is Science Friday from WNYC Studios. As you probably know, if you listen to the show, we're big fans of the microbiome, microbes that live in the gut. But one related subject that we don't talk about as much is what happens at the end of the gut. Yeah, I'm talking about what even scientists call the butt. But what is a but anyway? And why are so many scientists celebrating it for a whole week? But I digress. Science Friday's Daniel Peters Schmidt has the story. A few weeks ago, we saw a tweet that kind of caught our attention. Do you mind reading the tweet that you sent out back to me? Hold on a second. Let me get it up. Hello, does anyone know of any animal that has a few butts, like more than one but fewer than 100.

And I'm generally talking butts as the anus, but I'm open to other interpretations. That's Dr. Marine Berg, a scientist at the Joint Genome Institute at Berkeley National Lab. You probably aren't sitting around thinking about animal butts, but Marine is a part of a group of scientists and illustrators who think about them a lot. She got her start in invertebrate biology, and invertebrate butts, or invertebrates, have become one of her passions. She's even given public talks about them. I'm known as like the invertebrate butt girl on Twitter.

So anytime any like kind of new animal butt thing comes up, I always get tagged in these. It's just like a standard procedure at this point. Even though I do no research in this field, I'm just once again, I'm just the loudest person about this. Yeah. How do you feel about that of that being your calling card now on Twitter? I'm honored, honestly. It's... So now people tag her in tweets when certain discoveries are made.

There's a recent worm that was discovered that has a, hundreds of butts. That worm, Rem Silas Multikadada, isn't like most worms. Its body, segments, and branches out at multiple places, looking more like a connected series of cracks in a dried-up riverbed than a traditional worm. And at the end of each of these dozens of branches is an anus. I'm always looking for comic fodder and that one kind of wrote itself. Turns out, Maureen isn't the only one fascinated with invertebrate butts on Twitter. I thought, oh my goodness, I have to do a comic about an animal with a zillion different butts. Science Illustrator Rosemary Moscow put together a chat group, appropriately named butt chat,

and invited other butt-enthusiastic illustrators and scientists. I mean, what were your initial reactions to just being involved in this project? Oh, complete lack of surprise. Dr. Ainsley-Cigo, the curator of invertebrate zoology at the Carnegie Museum of Natural History in Pittsburgh, was one of the researchers who got invited to this butt chat. And like Marine, she'd also given a talk about bug butts before. She started a small document with some of her favorite butt facts. threw it into the chat, and the other members started adding to it.

I think at one point I said, oh no, we've opened Pandora's butt. Because there were so many different pieces of information flying in this chat. The group decided they'd team up and use their combined science and illustration powers for good by making comics about the backends of the backbone list. They're calling their celebration Invertebutt week, like Shark Week or Ceplepod Week, but for invertebrate butts. It's just a chance for some people who do science communication. to do the silliest thing that they can possibly think of.

We love talking about this stuff. Sometimes you get really tired of only covering the depressing news or only covering the extremely technical details. And this is something that's both educational and delightful, frankly. So we've got lots of information, but not an answer to the big question. What even is a butt? There's been discussions on science Twitter in the past about what is a butt. Is it just like kind of the back end of an animal or is it like the anus?

Some purest researchers are a little anal about this and believe that the word but should only be used when referring to fleshy buttocks. Marine and Ainsley have more generous views on this. You got one end where food comes in and one end where poop goes out. That second end is in my personal definition of the butt. It does get challenging when you think about questions like if a bug wore pants, would it wear them like this or like this? But I think we can conclude that what would we?

We in insect morphology terms refer to the abdominal apex is, I would say, with zero ambiguity, the butt region. So, yeah, context is very important on how you define it, but I'm flexible on definition. And for a bit more context, we have to go back hundreds of millions of years ago to the Earth's oceans. Most animals back then didn't have what we think of as a butt. Most just had a single multipurpose hole for eating and excreting. The descendants of some of these animals are still with us, like coral and jellyfish. But as you might imagine, that one road setup had some serious drawbacks. And so the idea with that is like you can only eat and then you digest your food and then you can get rid of your waste.

Whereas with us as humans, you can continue to eat as you're digesting. You don't need to wait for your whole digestive system to clear out before you eat again. So the whole even concept of like evolving an anus allows you to like basically eat and digest at the same time. So it's a little bit more efficient. The evolutionary marvel of the digestive system and subsequently the anus, was a big deal for life on earth. Animals got more out of their meals, bodies lengthened and grew bigger,

and developed better ways to move around, like swimming, walking, and flying, rather than, say, just existing, floating in the water like a jellyfish. What's a butt that you think that more people should know about? I mean, my favorite animal butt to talk about is the sea cucumber butt, just because it does a lot of weird things.

Like, it's not just one weird thing that does a lot. A lot of sea cucumbers, buts act as homes for other animals. Like you have the fish, you have crabs, you have a lot of things that live in the butt. And because, you know, maybe you don't want just any animal living in your butt, a lot of sea cucumbers have anal teeth to prevent certain animals from inhabiting their butt, essentially. Because what some will do is they'll get into the butt and they'll start kind of munching and gnawing on the gonads and stuff, which is obviously bad.

So they kind of have it all. They have like eating, breathing, defense, apartment building. Like, they have it all. And I really admire it. It would get like the most versatile butt award. Exactly. I want to talk about the face mite. The best part about them is that they don't have butts.

Franz Anthony is another science illustrator working with Rosemary on the project. The problem when someone doesn't have butts is that they can poop. So throughout their life, their body just gets longer and longer as their poop accumulates inside. And then once they die, they just burst open. And then the mite poop is basically all over people's faces. And I think that's really, really fun. And I don't like to pick favorites, but Ainsley's preferred butt might be mine now, too. One of my absolute favorites is the Neuroptrin family barothity.

Their type of lace wing, small insects with large clear wings, and their larvae live in termite mountains, which is a pretty dangerous place to grow up. Termites are essentially soldiers. They're territorial and dangerous, and they don't want any intruders in their home. So how do these seemingly defenseless larvae defend themselves when termites approach them? They turn around and wave their butt in its face and release an invisible but powerful gas that knocks out the termites almost instantly. So they're essentially farting them to death as a form of defense. And it's just one of the most beautiful things that nature has come up with in her infinite wisdom. That's the central thesis of Invertebutts week, which is let there be joy.

It's okay to have yourself a secret little chortle that's farting another animal to death. That's pretty great. I wanted to end on this question, which is, why should we care about butts? I'll take my answer off the air. Listen, I don't think that butts are necessarily the most important thing going on right now in society, but I think that butts are something delightful to think about. And looking at one particular body part of an animal can be a way to look at an entirety of an animal and look at the way that it experiences the world.

Yeah, I think but in general is just really funny because it's really accessible. Even kids understand it. So it is a gateway for kids to understand bigger concepts. And adults, too. I mean, I think, like, adults are already so excited about anything goofy and butt-related. So I think we all need to hop aboard the butt train and write it to Science Town. I'm so sorry. Invertebutte

But Week is currently happening. It started March 1st and it's going until March 8th. They're using the hashtag Inverta But Week on Twitter and you can draw your own favorite animal butt and tag it under that hashtag. We also have official illustrations from Rosemary and Friends and others on our site that you can check out. That's at ScienceFriiday.com slash butts.

For Science Friday, I'm Daniel Petersmith, National But Correspondent. And that's about all the time we have this week. And one big note next week, we are back in the studio. We'll be talking about the latest in research and treatment of long COVID. So we'll be welcoming your live phone calls and tweets. Have a great weekend. We'll see you next week.

I'm Ira Flato.