Science Friday - Gynecology’s Dark History, Antarctic Ice, Moon Craters. Jan 18, 2019, Part 2

Episode Date: January 18, 2019

Nineteenth-century physician J. Marion Sims has gone down in history as the “father of modern gynecology.” He invented the speculum, devised body positions to make gynecological exams easier, and discovered a method for closing vaginal fistulas, a painful, embarrassing and often isolating complication that can result from childbirth. But Sims’ fistula cure was the result of experimental surgeries, pre-Emancipation, on at least 11 enslaved black women, only three of whose names have been remembered—Anarcha, Betsey, and Lucy. Over a period of about five years, the women underwent dozens of surgeries as Sims attempted, and failed, to fix their fistulas. He rarely used anesthesia. What were the lives of those women like? A new play, Behind The Sheet, tackles this story from their perspective, imagining not just their pain, but the friendships they might have formed to support each other through surgery after surgery. In this story, the women tend each other’s ailments, make perfume to hide the smell from their fistula condition, and pledge to remember each other even if history forgets them.  Researchers monitoring the condition of the Antarctic ice sheet report that not only is the ice melting, but that the rate of ice loss is increasing rapidly. According to their estimates, around 40 gigatons of ice were lost per year in the 1980s. By the 2010s, that rate of loss had increased to more than 250 gigatons of ice per year. That melting ice has caused sea levels around the world to rise by more than half an inch, the researchers say. Eric Rignot, climate scientist at the University of California-Irvine and one of the authors of the report, joins Ira to discuss the trends in the ice sheet and what they portend for sea level rise. Our moon formed about 4.51 billion years ago and it’s been pummeled by meteorites ever since, leaving behind the lunar craters you can see on the surface today. Recently, scientists curious to know how often those impacts occurred came up with a clever way of determining the age of the craters. They discovered that many of them are relatively young—that is, the moon got hit by space rocks a lot more recently and a lot more frequently than scientists once thought. Sara Mazrouei, planetary scientist at the University of Toronto joins Ira to discuss the new research, out in the journal Science this week, and what it could tell us about Earth’s crater history. 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. Researchers monitoring the condition of the Antarctic ice sheet report that not only is the ice melting, no surprise, but that the rate of ice loss is increasing rapidly. And I mean, very rapidly. In fact, they found that over the past 40 years, the rate of ice loss has increased by about six-fold. So what are the implications? Joining me now is Eric Rigno. He's a climate scientist, University of California, Irvine, and NASA's Jet Propulsion Laboratory, and one of the authors of a report on the melting ice sheet published this week in the proceedings of the National Academy of Sciences. Welcome to the program.

Thank you. That must have been very surprising how fast that ice is melting. No? Wasn't surprising? Yes. It has been. I think the incentive of the study was really to try. to reconstruct a long-term record multiple decades.

The exact number, the six-fold increase in Antarctic mass loss, was probably not a complete surprise. But I was very sort of, we were very happy to be able to reconstruct these four years of data for the Antarctic. Give us some perspective on how much is melting. What is the massive amount of water that's melting? Yeah, so we're talking about, at present day, about 250 billion tons of ice that are sent in the ocean in excess of what the Antarctic should do to maintain the same mass. So that's a little drop of water compared to what's the Antarctic total volume of ice. But on the human scale, to put things in perspective, 1 billion tons is the consumption of water by sea. like Los Angeles over one year.

So Antarctica is dumping enough water to feed 250 cities like Los Angeles around the world for the freshwater supply. Can you actually detect ocean sea level rise with that much water? It's a very small signal globally. It's less than one millimeter per year. So that's not the real threat.

the real threat is the fact that we see this leakage of ice around the Antarctic in some critical sectors, and we know that with time these sectors will release even more ice and have the potential to raise sea level by several meters. So what you're saying is that the water can release the pent-up ice that's on the continent, and it will flow into the ocean? Yes. Every amount of ice that you displace from resting on land to floating in the air, the ocean displays sea level and sea level worldwide. That's amazing. Is the melting, is it melting evenly around the continent? Yeah, so the melting is actually a little bit of a dangerous word in the case of the Antarctic

because I would assume that audience would see the ice melting from the top and snow and melting and it's not the way it works in the Antarctic. The way it works is that the glaciers, the rivers of ice that control how much ice is flowing from the continent to the ocean are flowing faster. So they're sending more icebergs and melting more vigorously with the ocean than they did in the past.

The net effect is to have more ice melting in the ocean, but it's proceeding a slightly different way than we are used to when we talk about the glacier melting because of a warm climate. And what we knew before the study was that there was a lot of so-called melting in the Antarctic Peninsula, the little part of Antarctica that sticks out towards South America, and West Antarctica, a particular sector of West Antarctica,

and now we see that East Antarctica, a big sector of that, is also a participant in the melt. So the parts near the warm water are melting faster, the warming ocean is sort of a heat source? Exactly. All these parts that are melting rapidly right now are close to the sources of warm ocean, water. The places that are far away from these warm water are actually not changing at all. That's a little bit in contrast we are placed

at Greenland where we see melting everywhere in Greenland all around the periphery of Greenland. In the Antarctic, it's not affecting everything, but the places that are close to the warm water are affected and responding. Does the cold, the melting of the water and the

change in the ice, does that affect a larger climate system, like the winds that surround the pole? So the winds are affected by climate change, and they affect ocean circulation in the southern hemisphere in a way that pushes these subsurface, salty, warm water more towards the coast of the Antarctic. It's in this manner that it works. The feedback of that excess meltwater into the system is a little bit different. it might affect the formation of deep water around the Antarctic,

but it's a little bit of a trickle compared to the general pattern of ocean circulation around the Antarctic. How did you measure? How do you measure all that melting of the water? So it's mixing a large amount of data. We have to calculate what we call the flux of ice into the ocean. Our fast, the glaciers are transporting ice into the ocean, so we need to know the speed of that ice and the thickness.

The speed is measured by satellites, and we use satellites from five or six different space agencies. The ice thickness is measured from airborne radio echo sounding, and these data have been collected over the past decades by various programs. This way we can constrain how much ice Antarctica is sending into the ocean. And then we have to compare that with the accumulation of mass in the interior. And this is done by regional atmospheric climate models, in this case, models from the University of Utrecht in Netherlands. They employ what we call reanalysis data.

So it's an ensemble of meteorological data worldwide. They've been put together, massage and formatted together. And they run a high-resolution model in the Antarctic to, reconstruct exactly the snowfall pattern on the Antarctic and we use that to calculate how much ice should be coming out of these glaciers and compare that with what's actually coming out and the difference is the mass loss the net mass loss to the ocean so to do this accurately we need the most accurate velocity the most accurate ice thickness we need to bring this regional atmospheric climate model to a level of precision that that's uh

exceptional. Is there any reason to believe that this might, the rate of melting might slow down or stop, or is it going to get faster as time goes on? It's going to get faster for two main reasons. One is just the internal dynamics of ice. When you disturb a glacier, it starts responding slowly. And with time, as you keep pushing it, it responds faster and faster. It has a sort of a nonlinear response to climate. forcing. The other one is that based on our understanding of how the climate is acting on the Antarctic right now, I mentioned the winds that are spinning up more rapidly around the Antarctic continent and pushing more of its subsurface water towards the continent. This trend should continue as climate keeps warming around the planet and the temperature difference between Antarctic and the rest of the world keeps getting higher. Is there a tipping point in Antarctica where if you melt the, or if glaciers melt in the correct or the right place, you open up, you release like a dam that allows like a sudden flow of ice into the ocean?

Yes, there is something like a tipping point. In the Antarctic, you could probably argue that different parts of Antarctica have different tipping points, and we're not exactly sure what these are. tipping points might be. In the West Antarctic, we made an announcement four years ago that we thought we passed the tipping point for the Amitancy embayment part of West Antarctica, because the glaciers nowadays are retreating into a deeper ground with very little bumps and ridges upstream that could slow down their retreat. And we know from basic physics that when glaciers start retreating in the landscape where the bed elevation drops as you go inland, it's unstable. And the only stable state of these glaciers is to become completely afloat in the ocean.

So we think that we reached that tipping point already in Western Antarctica. How fast the glaciers retreat will depend on climate forcing will depend also on the course of humanity in controlling climate forcing. In the Eastern Antarctic, I don't think we've reached that tipping point yet on some of the key glaciers, but we're probably not too far from it either. How far is that not too too far? Well, to answer that question, we usually need to get to another level of details in our study. So in the case of the Western Antarctic ice sheet, for instance, I think we're going to be.

we had a good idea that something important was taking place there back in the late 1990s, 1997-98. We thought something big was happening there. And we waited until 2014 to sort of make a little bit of noise about the fact that we thought that the plug had been pulled in this sector, because in between we conducted very extensive surveys, surveys conducted not just by NASA, but by the National Science Foundations, by foreign entities like the British Antarctic surveys and others. We have to collect a lot of data, especially to characterize what the bed topography looked like

underneath the ice to sort of figure out, what kind of configuration do we have here? Is it conducive to a fast retreat or not? We have to make sure we map every little bump in the system before we say something. So in the Antarctic, we're not there yet. we need a little bit more work to figure out that level of detail. And a ridge and a bump here and there makes a difference.

All right, Dr. Rigno, we'll have you back when you get better figures on that. So thank you for taking time to be with us today. You're welcome. Eric Rigno is chair and Donald Brenn, Professor of Earth System Science at the University of California at Irvine. We're going to take a break when we come back. A new play explores the dark side of the research that brought us. modern gynecology. It's a new play that's the ensemble studio theater behind the sheet. We'll have a great interview with Christy Taylor, our science producer who went out and talked to the playwright.

We'll be right back after the break. Stay with us. This is Science Friday. I'm Ira Flato. Until last spring, New York Central Park featured a statue of Dr. J. Marion Sims, considered the father of modern gynecology. He invented the speculum, devised methods for easier examinations, and in 1855, he built the country's first women's hospital. His biggest breakthrough was devising a surgical cure for a common complication associated with childbirth. But his success came at a huge cost, the pain and suffering of nearly a dozen enslaved black women who were his experimental subjects. A new play behind this sheet takes a closer look at what the daily lives of those women might have been like and the ethics of his work. The play,

is running at the Ensemble Studio Theater in Manhattan. SciArts producer Christy Taylor sat down with the playwright. Charlie Yvonne Simpson, and here's that interview. Charlie Yvonne Simpson, welcome to Science Friday. Thank you. It's so good to be here. So I know I first heard about J. Marion Sims when the controversy over his statue got a lot of publicity last year. I had never really thought about where gynecology came from. But it turns out Sims was this Alabama plantation owner who everyone kind of thought was crazy

at the time. What was his life like? Who was he? It seems like he sort of fell into medicine. You know, Sims was trying to find his way and sort of fell into this complication of fistula's and sort of just found this thing that he could sort of hone in on and really try to figure out. And then, you know, it's sort of fascinating sort of what he did afterwards. You know, eventually moves to New York and he opens a women's hospital. And it really does seem sort of like this discovery of his changed the direction of his life. It wasn't looking too exciting before that and things got interesting. Yeah, and you mentioned those fistula.

What exactly is a fistula? The way that I tend to describe it is fistulaes usually occur when, you know, during childbirth and the baby is going through the birth canal and gets stuck. And the baby's head will push against the birth canal. And if it's doing that over an extended period of time, the skin that it is pushing into loses blood flow and it dies. And what can occur is that these holes are formed in the birth canal. And sometimes those holes are between the birth canal and the urethra. And sometimes it's between the birth canal and the rectum and urine and or. or feces can then go through those holes,

thus creating a situation where a woman feels like she's constantly leaking these bodily fluids end is in pain, obviously. Yeah, and Sims, who you named George in the play, he was really determined to fix them. So what was he doing? Who were these women he was experimenting on? You can actually learn a lot. He wrote an autobiography called The Story of My Life,

and he goes into the stories of three of the women that he worked on, Anarka, Betsy, and Lucy. What you gather from reading it is that you had these plantation owners who would end up with these women, these slaves, who had this issue, which, you know, we're talking about slavery. Black women during that time were breeders. That was part of our quote unquote usefulness. And so suddenly you now had these women who were in constant pain who smell terrible and are not in a position to have children and maybe not even in position to do all the work that they used to. And so these plantation owners found their way to doctors. Sims being one of them being like, you know, what is going on? How can we fix this? And at first, Sims was sort of like, I don't know what to do, you know, and kind of sent them back on their way. And it was actually working on someone else who had a completely sort of different problem, but he sort of discovered that he could get a really good look inside of a woman and thus at fistulas if he sort of fashioned a tool to look in. And so that's actually how we

get the speculum. And so that's sort of how we begin these years of experiment. You then find out that it took him about four years to actually figure out how to fix fistulas. It still seems a little bit unclear. Like he was trying different methods, different materials, you know, silk sutures, lead sutures. Those four years was him really just trying to figure out how can I close this hole in this delicate part of the body. It's so simple, but it's like you have to close the hole completely. You know, in the play, one of the character, George says there's no halfway with this, a hole as a hole. You know, these women would not be fixed if any urine or any feces could still escape.

He would get close, but he would be left with these little little holes. And it wasn't until he figured out silver. Silver sutures would be great. And a certain way of creating a suture that sort of allowed the body to sort of cover itself with new skin. did he sort of solve the issue. There are some accounts that claim these women consented to or they asked to have these surgeries tried on them. But you seem to think otherwise

or portray otherwise in this play. Here's a recording from a scene in the play where a newly arrived slave, Dina, is being told what's going to happen to her. We should get you moving. Master George won't like that you're still here and not resting. He'll want you rested before he tries.

Tries. Well, all he did today was remove some of the rotten parts of you? No parts of me. All right. I just mean the parts of you beyond fixing, the parts of you that have already died. He had to clear those away, and then once you heal, he can try to close the hole. At least that's what those papers say. How many times do you try on you?

A few. You ain't fixed yet? Not yet. So he can't do it. You were helping him get there. What if I don't want to help him? When's the last time anything that we wanted mattered for anything? Besides, he bought you.

You're his now. Could they have consented? You know, I've read, you know, there have been several articles, especially since, all this talk of the statue has sort of come up. And, you know, some say that, oh, the woman must have consented because of where the fischulas are, the part of the body, you know, they had to agree to sort of lay there and open their legs. And here's my thing.

You were talking about women who were enslaved. And being enslaved means you are the property of someone else. That means that you do not. own your own body, your own self. So the idea of consent in a world where these women, you know, weren't even really considered fully human, seems, for lack of a better phrasing, seems a little bit ridiculous to me. This is not to say that maybe, you know, their lives weren't fantastic. They weren't, they were in pain and they were uncomfortable. Of course, they probably, you know, here's somebody saying, I'm going to try to fix it. They may have been like, okay.

you know, that sounds like a good plan. But they're okay, I don't think, would really have any effect on whether or not they would be experimented on. Obviously, I wasn't there, but I'm going to sort of push against this notion of consent. Also, you know, surgery number one, maybe they're like, okay, maybe this will end up okay. Anarka is experimented, was experimented on 30 times. So at what point, you know, if at surgery number 15, she suddenly was like, actually, I don't want this, you know, I'm not convinced that her saying that would have any effect on whether or not the experiments continued. So this notion of consent when, you know, with people who society was not giving humanity to seems really, really at odds.

I have a hard time even really using the word consent when it comes to what these women could have done or could have said in terms of the experiment. You mentioned the number of surgeries already. That really stood out to me as well. They were operated on nearly as soon as they had recovered from the last one sometimes, that they would get infections between. He would have to clear the infections out. Here's another clip from the play where a slave named Philomena is talking to another slave named Lewis about her surgeries. Well, how many surgeries have she had? Fifteen about. And how many on you? I feel like you in there every other week. You can't be in there every other week. Fears like it. I just tend to heal up faster than the others. So it has been quite a few times. He says I'm a better candidate than some of the others. Shouldn't you be getting off to bed, Lewis?

Yes. How many times? I've lost count. Philemena. 20? 25? I don't know. 28.

I'll be going in for 29 soon enough. The lead sutures didn't take. And Charlie, they weren't given anesthesia, were they? Mm-mm. This is one of the points that people bring up. a lot when it comes to Sims and, you know, the fact is that these women were operating on numerous times without the use of anesthesia. Now, anesthesia at the beginning of his experiments wasn't widely used. There were people that were beginning to use it, beginning to understand it.

Some of the research that I have done, you know, it does seem like at least towards the end of his experimentations that ether anesthesia, you know, could have been used and wouldn't, you know, would have been used in other situations. But, you know, something interesting about Sims is that even after he sort of figured out the closing of fistula, he still didn't use anesthesia on most of the women he was working on. Including white women. It's actually something I've read since I really wrote the play, that he just didn't think that pain was worth it, you know.

But I've also read things where that. that he had used it on white women. So, I mean, that's a lot of the things that I realized in the researching of the plays and making the decisions for the plays that, you know, I will read one thing and they will be like, oh, yeah, no, he definitely did. And I'll read something else. And they're like, I actually don't know if he did. What we do know is that he did not use anesthesia on these women and really didn't believe

the pain was big enough for anesthesia to be used. So they had to hold each other down. Yes. So these women, again, we're talking about pain in an extremely sensitive part of the body. They were almost like the nurses in these experiments. And in fact, there are articles like there's something I read a few years ago that called them the mothers of gynaecology. These are the mothers of gynecology if we're going to call Sims the father. And because they were in the room, they were holding each other down.

They were cleaning dressings and sort of doing the labor that wasn't. just focused on the closing of a fistula. One thing that I found really powerful and really uncomfortable at the same time about this play is how you don't shy away at all from the physicality of it. Your actors talk about leaking and smells and pain over and over and over again, and the word leaking really does come up many times. You really wanted us to shift uncomfortably in our seats during this, didn't you? I mean, I think something that was extremely,

and is extremely important to me in the play and sort of looking at this history is acknowledging what the women went through. You know, we can have complicated conversations about consent. We can have these conversations about whether or not he either anesthesia was used or whether or not he used it. Did he use it on black women? You know, we can have all of these debates. But at the end of the day, we had a group of black women. we know three of their names, but there were more who went through these surgeries, and they went through it, and it was painful. And it felt important to emphasize that. And to really have it hit

home, I can't imagine what it would be like to experience what a fistula is and what it is to feel like you're leaking and dripping and have no control of that. I mean, In society as it is, you know, we have all these products to make us smell better. And that's just like on a normal day. So I can only imagine what it felt like, what these women experienced, how other people treated them because of this complication that they ultimately had no control over. And it felt really, really important to be like, yes, we can have all of these debates. But let's actually take a moment and acknowledge what physically. happened. I'm Christy Taylor, and this is Science Friday from WNYC Studios. And in this play,

you not only try to imagine the pain that they must have felt and been through, but you give them lighter moments as well. You've also imagined sisterhood. They make perfume. They have hopes of romance. They laugh together. How true do you think that part is? I hope it is. I like to believe, you know, these were women who were intimately a part of each other's lives, you know, as you mentioned, You know, they're holding each other down. And so I really hope that they had a intimate and close and ultimately loving relationship. But, you know, I also, you know, personally, you know, I am a black woman and I have ancestors who were enslaved. And I can't imagine what that must have been like.

And one of the ways in which I guess I can even begin to fathom surviving those circumstances is imagine. that my ancestors had people to love and to laugh with and to ultimately live with, to give them back the humanity that the society at the time stripped away. We're also talking, you know, a lot about pain, and I am, I was not and continue to not be interested in re-traumatizing us and having us, you know, having the only takeaway be pain. You know, I was interested in showing these women's humanity. And part of humanity is fighting to find joy. Sometimes it's fighting with each other.

It's pushing back. It's making perfume as they do in the play. Are we supposed to hate J. Marion Sims after this play? I mean, I leave that up to you. I can only answer that personally. And personally, I don't hate Sims. I think that J. Marion Sims, like many other, and scientists and just people at the time lived within an evil system, which we call slavery,

that put white people above black people and took away black people's humanity. And that is terrible and that is evil. And I hate that. And I hate that that system allowed for what we now look back on as racist practices or practices infused with racial bias. to take place. That said, I also acknowledge the fact that Sims' work was important. Figuring out how to close fistulas helped not only black women. It did help white women and other women throughout the United States and throughout the world, quite frankly, even as the procedure may have been refined.

And his work, you know, led to him opening a women's hospital here in New York City. He's called the father of modern gynecology for a reason. You know, I go to the gynecology. They use a speculum. You know, I can appreciate that. But I think it is important for me, and I hope for anyone sort of seeing the play, to be able to hold that, to be like, yes, this is, you know, good job. Sims, you figured it out. But you don't have to agree with the way that he did it. You don't have to like it.

And we don't necessarily have to forgive him for his methods. I think it's more important to hold both of those. things to hold the good that he did and hold the bad way that he did it and and somehow learn to honor both sides of that. You know, personally, I think that that's something we could do better of in general and not necessarily having to fall one way or the other. I think, too, the thing I am actually, what I hope he believe with even more so than that is these women, because the thing that actually upsets me more is like the conversation

about whether he's good or bad or evil, actually just totally ignores the fact that these women were there. And these women deserve to be honored and remembered in the same breath that we remember Sims, if not before, we remember Sims. And we're out of time. Thank you so much for being here, Charlie. Thank you.

Charlie Yvonne Simpson is a playwright living in New York. Her most recent work is behind the sheet, running at the Ensemble Studio Theater in Manhattan until February. Thanks also to actors Jahan Young, Naomi Lorraine, Sean Randall and Christina Pitter, whom you heard in clips from the play earlier. That's SciRat's producer, Christy Taylor, and you can hear the full interview part you haven't heard on the air can be heard on our podcast. We're going to take a break, and when we come back, we're going to talk about the lunar eclipse. Stay with this.

I'm Ira Flato. This is Science Friday from WNYC Studios. This is Science Friday. I'm Ira Flato. If you're planning to take in the super blood moon eclipse this weekend, you'll get an opportunity to gaze at. at the lunar surface and its many, many craters, that totality is going to last over an hour. And perhaps as you watch,

you'll also wonder, as astronomers have, just how old are the craters there? For close to 4.5 billion years, the moon has been pummeled by meteorites, and scientists are curious to know how often those impacts occurred. Was the moon struck once every million years, every two million years?

What? Now, how would you tell from far away here on Earth? Well, some clever researchers divides a solution and discover that many of the craters are relatively young. That is, the moon guide hit a lot more recently and a lot more frequently than scientists once thought. They published their work in the journal Science. Here to tell us how they did it, and what this could tell us about the Earth's impact history, is Dr. Sarah Marui. She is planetary scientist at the University of Toronto. Dr. Masrui, welcome to Science Friday.

Hi, thanks for having me. Excited to join you today. We're excited to have you. So what got you interested in studying the moon? In general, I've been interested in what I call airless bodies. I know it sounds funny, but asteroids, moons, things that don't have surfaces because they can tell us a lot more about the history of the solar system. Dr. Maseruri, why are you interested in knowing the age of these moon craters? It's been a mystery, right?

We're all wondering how old are these craters on the moon? There's this well-known late-bombardment-heavy period that started when the Earth and the Moon were forming. But in the past couple of billion years, we thought that the bombardment rate had been constant. So I've been interested to know how old the craters on the Moon are because they can tell us a lot more about the Earth and our own history as well. And that's a tough thing to do if you're not on the moon.

Definitely, definitely. It would be a lot easier if we could have a bunch of astronauts collecting samples right now. Would you like to be one of those? I would love to. Are you hiring? Hey, you got my, I'll write your letter of recommendation right now if you'd like. Okay, but you're not there yet. So you came up with a really clever way of determining the age of these craters.

Tell us about that. Yes. So actually, my PhD supervisor, Dr. Rebecca Gant, at the University of Toronto, pioneered this new method to date young craters on surface of the moon. And it's a brilliant way. We've got the lunar reconnaissance orbiter, NASA's mission orbiting the moon since 2008, and it's got an instrument called Diviner on it, and it measures temperatures on the surface of the moon. We use the nighttime temperature from the moon to try and determine how rocky different parts of the moon are. So really young craters, for example, once you've got a fresh impact, it excavates a lot of rocks and these big chunks of rocks are going

to sit on the surface, and in about a billion years, they're going to get broken down into smaller pieces from future impactors. And this idea uses the fact that big rocks stay warm throughout the lunar night. It uses the concept of thermal inertia. It might sound fancy, but we're all super familiar with it. when we go to the beach on a hot summer day, unlike today's really cold weather, during the day, both the sand and the big rocks get warm. But as soon as the sun sets, the sand gets cold, whereas the big rocks stay warm throughout, they can stay long for, they can stay warm for longer. It's the same concept on the moon.

The big rocks stay really warm throughout the night, whereas the sand and the stuff that has been turned down into sand are cold. So we use that to determine the ages. So as craters get older, they become less rocky. And we use how rocky they are to determine their age. So if you see a crater with a lot of big rocks, you know, it's younger. Exactly, exactly. And what makes them? I mean, there's no weathering, right?

I mean, there's no wind. There's no rain on the moon to weather these rocks. Do they just crack apart? And how did they get smaller? So the moon is constantly being bombarded by stuff, things of different sizes. So future impactors of smaller sizes, they keep breaking down those rocks into smaller and smaller pieces. Also, the moon experiences big temperature changes, and that causes stress on the rocks, and it helps it further break down. What did you discover about the timeline for the crater impacts on the moon?

From your paper, it chose that there was a little jump in action, right? Right. So our method is only able to date craters younger than a billion years on the surface of the moon. So we started collecting data for all of the big craters on the moon that are younger than a billion years. And once we started to look at their ages, we saw a jump at about 300 million years ago. We saw a jump by a factor of about 2 to 3. Wow. Yeah, the rate has been almost tripled in the past 300 million years.

Any idea why? Maybe there would be a jump like that? Yeah, so there is a few hypothesis for it. A big one is that there may have been a breakup in an asteroid family. So asteroids live in the asteroid belts between Mars and Jupiter, and sometimes two of these large asteroids or more collide into one another, and they get broken down into smaller pieces. And as they absorb heat from the sun and re-emmit the heat back,

they start to shift in their spot, they start to move around, and eventually they exit their orbit, and they start moving towards the inner solar system, so towards the Earth and the Moon. You can think of it as a landslide starting at the top of the mountain, and think of the Earth and the Moon as a house in the valley. So we see the footprints of those broken pieces of asteroids as craters on the earth and the moon.

So something happened that hundreds of million years ago, all of a sudden you had more bombardment? Yes, so an asteroid family broke up, and they started to move towards the inner solar system, and that caused more of a bombardment. You let some people use your data, I understand, to create a piece of music that represents these impacts on the moon using sound. Give us an explanation of what you did.

Yes, so system sounds was kind of, enough to take our lunar data and turn it into a video and also into sound. So they've turned the last one billion years, the history of the impact of the moon, into sound where every note represents the size of an impact crater, and you can hear the frequency of the bombardment, and they've been doing more turning into astronomy and space data into music so that they can make science more accessible, especially for those that are visually impaired.

Well, let's listen to that clip now. Yeah. Sounds like a moon, a lunar wind chime. Sounds beautiful, except it gets a little bit scary towards the end. Maybe we'll, let's play it again for people who we just, let's play one more time, let's hear. This is the sound of craters on the moon. No, not scary. Beautiful.

It is. And you said this can tell us something about the Earth's crater impact history, too. Right. So the moon is the closest neighbor to the Earth. Earth. So both of them must have experienced the same bombardment history because anything that would hit the moon would also hit the Earth, even more because Earth is larger and has a bigger gravity. But until now, we thought that a lot of, even the large craters on Earth, we're talking about craters larger than 20 kilometers. We thought that they would have experienced a lot of erosion and that we wouldn't have had a complete record on Earth. But looking back at the Earth crater history, on stable terrains where we have large craters, we actually see a similar signature between the two. So looking at craters on Earth, we see the same increase in the past 300 million years. So we also on Earth have been getting bombarded by more stuff in the recent years.

But a lot of the craters that on Earth have eroded, right, because we have all that weather going on. Exactly. So we have a lot of, we have wind, we have an atmosphere, a lot of erosion that would have affected smaller-sized craters, but when we talk about 20-kilometer craters, erosion wouldn't have played an effect on stable terrains. So the areas that we've looked at, we've obviously excluded oceans or the Amazon Basins, places where we would have experienced a lot of erosion. We've taken places like the Canadian Shield, where we know those rocks have been stable for millions of years. We have a caller who asks, since the moon is tidily locked with the earth, Can we learn anything about the difference between impacts on the far side and the near side?

That's a really good question. There are some beliefs that maybe the near side and the far side or actually the leading and trailing edges of the moon, so the heading side and the trailing side of it would have experienced different amounts of bombardment. But looking at our data, looking at really young, large craters on the moon, we don't see a difference between the two. So the bombardment has been very similar on both sides. What does the other side of the moon look like?

I know there's a Chinese rover over there now, sending back photos. Does the other side look a lot different than the side closest to us? It does look slightly different. So the lunar reconnaissance orbiter that's been orbiting the moon has been collecting data since 2008, and we can see both sides of the moon. We can see both sides pretty well. the near side of the moon, the side that faces us, we see more of darker patches, what we call Maria, which means C's in Latin's. So those are darker features, but the far side of the moon doesn't have those dark features as much and just looks more bombarded.

I see you caught yourself when you were going to say dark side. No, definitely not the dark side, is it? Definitely not, no. It's just the far side, the other side. Because it's facing the sun. Exactly. We just doesn't, just doesn't face our side. Exactly. Can the moon shield us, shield the Earth from any possible impacts from space?

Not really, no. The moon is too small. So the moon's cross-section is less than one-thirteenth of the Earth, and it's about 60 Earth radii away from us. So it would be like wanting to protect yourself with a bulletproof vest that was created for an action figure. So it would be too tiny. You know, we talk a lot about possibly going back to the moon, and I know you said you would like to, but don't send your letters now to NASA. It goes, NASA shut down.

Oh, I know. I want to ask you a question, but first remind everybody that this is Science Friday from WNIC Studios. Yeah, NASA is shut down, right? There's no one there to take a phone call. If we were to go to the moon, what would be the best place you would like to go to? What, in terms of understanding the age and being a rock hound on the moon? So on the far side of the moon, there's the oldest terrain, and there's a big impact basin. It's 2,000 kilometers in diameter.

It's called the South Pole Aiken Basin. And because it's so large, it's thought that it could have brought up material from the lunar mantle. So a lot of the scientists are keen to get samples from the South Pole Ocean. Aiken Basin, and I would put all of my eggs in that basket if we were going to send one mission to bring samples back. Are you excited about the moon eclipse, the lunar eclipse happening this weekend? Absolutely. Absolutely.

It's very cold here, but I'm going to bundle up and try to watch at least a few minutes of it. And the reason, you know, the totality lasts for like over an hour, does it? It does, yeah. And that's because why? Well, the totality lasts about an hour, but it's also a super moon. this time around. It means that the moon is at its closest orbit around the Earth. So we would get to experience it for a little bit longer.

But we're also experienced a total lunar eclipse so that the entire shadow of the Earth would be covering the moon. So it would give us a lot of time to go out and check it out. Yeah, I guess the closer we are to the moon closer it is to us, the larger the shadow size. Yeah. So it's a pleasure talking to you. Same. Thanks for having me. It's been great.

And I wishing you a good look on watching the eclipse. Thank you. You too. Bundle up. You bet you. It's like to Sarah Mazrui is planetary scientist at the University of Toronto. And speaking of which, one last thing, speaking of the moon and this weekend's total lunar eclipse, what's the best way to see it? Well, of course, we asked Dean Regis of the Cincinnati Observatory to give us a sneak preview. The sun, moon, and Earth will be lining up this weekend.

We're going to be having a total lunar eclipse. But the big question is, what day is it? A lot of media outlets are saying it's going to be on January 21st. Well, not so if you're in the Western Hemisphere for the United States, North America, South America. It's going to be the night of Sunday, January 20th. So mark your calendars. Don't go out on the 21st. You will miss it.

I want to share a couple tips on what to look for. I have a couple favorite things to look for and favorite times. So here's the schedule. This is what's going to happen. First contact, the first time you're going to see the shadow of the earth on the moon. will be at 10.33 p.m. Eastern standard time. So adjust your time accordingly. I always like this part because that's when the eclipse starts and you're like, wow, it's right on time. I love the precision of it and starting to see the shadow. And then the shadow will slowly sweep across the moon and totality begins at 1141 p.m. and goes

till 12.43 a.m. That's when the moon is totally in the earth shadow and turns all sorts of cool colors like orange and red and all sorts of bloody colors. And so you can check it out and see how the light changes and how the colors change from minute to minute. It's very cool. And then the shadow wipes away and the moon returns back to its normal self at 150 a.m. On the morning of the 21st, but remember, you got to start watching on the 20th.

So Sunday night, get ready for this because the next total lunar eclipse won't happen until 2021. One last thing is speaking of the moon this weekend, that eclipse that Dean Regis of Cincinnati Observatory is telling. us about it's also a good opportunity. As we heard, as Dr. Musrui said, you've got to bundle up to go out and see it, but you can also use that opportunity to go see the other stars in the planet since the moon will be

very dark, you'll be able to see the other planets and stars coming out. So that's really a good opportunity to do some winter watching in the cold weather. Hopefully, storms coming across the country will not upset. Every time I want to go out and see an eclipse, there's always a cloud there or something that's getting in the cold. the way. Speaking of going out, just a quick note to let you know that I'm going to be going out. I'm heading off for a few weeks to Southeast Asia, going to see Anger Watt, a lot of other sites in Cambodia, Vietnam, Thailand, and John Dan Kowski, who does such an able job filling in for me when I'm away. He's going to be here filling in for me. And I'm going to be trying to

send back a few dispatches from the road. So maybe catch up on what I've seen, share with you with stuff that's going on. So take good care of John. John. Well, I'm gone. He's such a valuable asset to us all. I'll see you soon. BJ Leiderman composed our theme music, and if you miss any part of the program, you'd like to hear it again. You know, we have our podcast, and we're on social media. You can ask you a smart speaker to play Science Friday. So literally, social media, smart speakers, every day now is Science Friday. Have a great weekend. I'm Ira Flato in New York.