Science Friday - Ant Socialization, Smoky Skies, Dust Storm, Mars Lake. July 27, 2018, Part 2

Episode Date: July 27, 2018

Many ant species have a queen, the member of the colony that lays eggs. The rest of the ants are divided into different roles that support the queen and the colony. So what ants become queens versus workers? Scientists found that the gene ilp2 that regulates insulin played a role in determining what ant becomes the queen. Biologist Ingrid Fetter-Pruneda talks to John Dankosky about how this gene works in determining a queen. The Rocky Fire and the Jerusalem Fire scorched nearly 100,000 acres in northern California in July and August of 2015… and when the prevailing winds were right, smoke drifted all the way down into the San Francisco Bay Area. That’s when locals began tweeting their observations. Now, scientists at the U.S. Forest Service have analyzed 39,000 tweets like these from the 2015 wildfire season, and found that social media data can be a reliable way to augment existing air quality monitoring data in predicting the extent—and the public health effects—of wildfire smoke. Sonya Sachdeva joins Science Friday to talk about how tweets can be a useful tool in tracking wildfires. Plus: Earlier this month, a cloud of dust rolled into the atmosphere above Texas and the Gulf Coast. It was a remnant of a storm blown over from the Saharan desert. But, according to a new study, that Saharan dust also brings with it a silver lining—it suppresses the formation of major storms. Bowen Pan joins John Dankosky to explain why a dusty atmosphere could mean a less severe hurricane season. Researchers have been scouring Mars for water since the early 1970s. Since then, they’ve found frozen water in the poles of Mars as well as trace amounts locked up in Martian soil, but nothing liquid—until this past week. A team of scientists from Italy’s National Institute of Astrophysics announced in Science they found liquid water underneath the glaciers of the planet’s south pole. Angel Abbud-Madrid joins John to talk about how the researchers found the liquid water and what this discovery means for future Martian water research, and Bonnie Meinke tells SciFri the best ways to see Mars as it will be the closest it’s been to Earth in 15 years.   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 John Dankoski. Iraflato is away. Living in a social group is complicated. You have to consider others, not just what you want and your own needs. Everyone needs to cooperate to organize all that needs to get done. And there are certain roles that need to be divided up to make the structure run. There are workers in the higher-ups. This might sound like your office, but this also happens in the animal kingdom too. A group of researchers looked at how this occurs in ants, especially the division of roles in the colony. They wanted to know how. How does an ant become a queen or a worker? They found out that it's based on genetics, but not the way you might think, not in terms of who is related to whom, but they were able to pinpoint a certain gene that played a role in determining which ant becomes the queen. These results were published this week in the journal Science. My next guest is one of the authors, and she's here to tell us what this means about the evolution of social organization in the natural world.

Ingrid Fetterpraneda is a postdoc research associate at Rockefeller University here in New York, and she joins me in our CUNY studios in Midtown Manhattan. Welcome to Science Friday. Thanks for being here. Thank you so much. Our number is 844-724-8255. That's 844-Sight-Talk if you have questions about ant behavior. So before we get directly into your study,

I'm wondering if you just take us inside the typical ant colony. There's a queen and what other kinds of ants? Well, you have a queen and the workers, and the workers normally do the foraging tasks and the nursing tasks. And then depending on the ant species, you can also have other types of workers, like the soldiers. And these typically have, like, huge mandibles. I don't know if you have seen them. Oh, the huge mandibles, they're just the pinches on the front.

Yeah. And that's in another kind of ant colonies. And there's thousands of types of ants, right? And they all behave slightly differently, or are they all more or less organized the same? They are, there is a lot of diversity, but they are more or less organized the same. And they all have, well, most of them have queens that are the ones that reproduce and make eggs and then the worker class. So ants weren't always as social as they are now. They evolved from an ancestor that was a bit more solitary.

What can you tell us about that? Well, first you have to imagine that you would lay an egg, like the ancestor would lay an egg, and then this egg would hatch into a larvae and would have to feed and develop, right? So what first happened was that something similar to a, well, probably a wasp, would parasitize something and lay an egg there. And then these larvae would hatch there and eat and then develop. But then the actual ancestor to ants started providing food to these larvae. And that's like the main issue responding to the larval cues to the need of food. Why exactly is it advantageous for an insect to become social?

I mean, what's the evolutionary advantage to developing social behaviors? It's a very difficult question, and I don't know the exciting answer, but what happened was that it made them more successful, and you can have, for instance, a colony with just one queen laying all the eggs and due to this reproductive division of labor, and 10 millions of workers helping raise the young of this queen. So it made them extremely successful, just the fact that there was brute care and generations, overlapping generations.

And you say brood care. So this is lots of workers taking care of the young, essentially. That's their job. Yes, exactly. So in your study, you were interested in figuring out if there was a difference between the genes expressed in Queens versus workers. you found that there's one gene that was common in the brain of a bunch of ants. First of all, tell us how you pinpointed this one gene.

Yeah, so what we did is we compared across seven ant species. The genes that were being expressed in brains of queens and brains of workers. And we found that there was this gene, which happens to be an ant-insulin, who was always highly expressed in Queens and low in workers. But it was by comparing the seven distantly related ant species that we were able to find this one gene. So you're saying this is a type of ant insulin. How are the insulin levels in reproduction related?

So it's related to metabolism, and also in insects is known that it regulates how many eggs you can produce. With higher levels of insulin, you can produce more eggs. And you also increase, like, the nutritional stores. And due to increased nutritional stores, you can increase the amount of eggs you produce. And that's all regulated by insulin. So at the top, we were talking about this difference between the worker aunt and the queen aunt. And I'm having read through your study and having tried to decipher this, I'm still a little, I'm unclear.

I want to understand. And how is it determined which ant becomes the queen and which ant just goes around being the worker? Is it predetermined in some way genetically, or is there something specifically that happens to one ant over another? So they are in many ants, in most ant species, they're all genetically identical. And what happens is that due to differences in development and the amount of nutrition that they get, there's like a variability in the size.

And some will therefore have more insulin. and that's what we found. And they would also have more ovaries. But we tested all these in the ant species that we study in the lab. So we were able to test our hypotheses and specific ant species that we have. But it's related to amount of nutrition and development. Yeah, but genetically they are all identical. So in your study, you were actually giving some of these worker ants,

these ants that weren't reproducing a shot of insulin. Yes. Right? So explain exactly what you did and what you found. Yeah. So we study a very interesting and special ant in the lab that it's the clonal raider ant. The clonal raider ant. Exactly.

And what's interesting about this ant, I'll tell you briefly about this ant and then how we injected them and tested the function of this insulin-like peptides, right? So the clonal raider ant, all the ants in this colony look the same. You don't have a real queen. However, they behave like queens for two weeks, and then they behave like workers for two weeks. So it's a different kind of ant species to the ones we were talking at the beginning. And so what we did in these ant species also when they behave like queens, they have higher levels of insulin, and when they behave like workers, they have lower levels of insulin.

And so what we did is we got the ant insulin, and we developed a protocol to inject them, and we injected and elevated the levels of insulin in ants. And in ants that were behaving like workers, and we were able to activate their ovaries, and therefore they were starting to produce eggs. And what is interesting is that what we discovered, well, is that, again, the larvae, the young in the colony, are repressing the ovaries, the sites of egg production in these ants.

And once you remove the young, The levels of insulin in the end go up, and then they activate ovaries and behave like queens. Okay, so if there's larva around, the ants are essentially being told to not reproduce and to take care of the larva. That's their job now. Exactly. And as soon as the larva go away, the ants essentially something kicks on and says, okay, no more larva, we've got to make new ants. Exactly. And that's how it works.

Yeah, so, yeah, and that's fascinating. I mean, how these gene became or regulated, or not this gene, but the signaling, insulin signaling in general, became regulated by the presence of the larvae or the young, you know, the social context. That's what is fascinating. Now, when you say social context in this context, what exactly do you mean? Because, I mean, for us humans, when we think of socialization, there's an awful lot of things that go into that, how we behave socially. When you're talking about social behavior and ants, what exactly are you talking about? Well, I'm talking about, there are many things that they do that are amazing, but in this specific case, I'm talking about the fact that they take care of the brood of their young, you know? So the social context means that there are larvae present in the colony. And in this end that I'm telling you that we study in the lab, in Daniel Kronauer's lab, the larvae always are present during this cycle, so they are all the same age. And then at some point they pupate, and then you don't have young anymore that are hungry. and that need to be fed.

And once they pupate, then the adults can, again, lay eggs and produce a new cohort. So that's very interesting. You said that there are many amazing things that these ants do, and you kind of got a smile on your face. You really, I mean, you find these ants fascinating in all sorts of ways beyond just this study. Yeah, definitely. I mean, give me something else. What's something else fascinating that they do in a social setting? Yeah, well, they help each other.

They cooperate, not just to rear the brood, but for instance. They build their nests together in other ant species, and they do that by holding their legs together, for instance. Or they make bridges. There are many examples. Or they, yeah. But these study in specific really gave us a lot of information of how the social environment, which I mean by the presence of larva, was regulating the behavior of the ants, no? The reproductive behavior of the ants. Is there anything that we can learn from these ants that you're studying about?

species outside of ants, about other organisms? Is it teaching us something about socialization? I would definitely say yes. We have learned a lot about studying model organisms like yeast and flies about how genes work

or what the function of genes are. We have learned a lot about studying seaslux and not just seaslux but giant squids. And now we have the opportunity to study something really complex that is social behavior in a simple organism that is an ant.

So I think we will learn about even human social behavior eventually by learning the basics of how such a complex system can work. And that's what you mean by a model organism, an organism that is able to teach us about others. Yeah, that is able to teach us about others and that we can do very controlled experiments

in a laboratory setting. So what's the next thing that you're studying? What are you working on now? Well, we're starting also worker division of labor. So this was a reproductive division on labor. What makes them queens and workers and how this could have evolved,

which is a fascinating question. And so the next thing would be what makes them to behave like nurses or like foragers, for instance. That could be another. So is the real division of labor in terms of who's going to do what to make sure that the colony works

beyond just reproduction? Yes, exactly. It's fascinating stuff. Thank you so much for bringing us these ant stories in your study. I really appreciate it. Thank you so much. Ingrid Petterpraneda is a postdoc research associate

at Rockefeller University here in New York. and she joined us in our CUNY studios. Coming up after the break, how the Forest Service is tracking wildfire smoke with your tweets. Stay with us. This is Science Friday.

I'm John Dankosky. The West is burning again. New fires exploded up and down the state of California this week, killing several people, and the Ferguson fire, which forced Yosemite Valley to close, is only a quarter contained.

As the expression goes, where there's fire, there's smoke, and a lot of it. It can sometimes be hard for authority, is to track where all that smoke is going, what the public health effects might be, depending on where the winds blow. So they're looking to a new source of data on that smoky air pollution. Your tweets. Joining me now to talk about using social media data for air quality prediction is Sonia Suchdeva, who's a research social scientist with the U.S. Forest Service Northern Research Station in Chicago, and she joins us from WBEZ. Sonia, welcome to Science Friday.

Thanks so much for being here. Thank you so much for having me, John. So, first of all, how do we currently track wildfire smoke, monitoring stations, that sort of thing? Yeah, right now, the most robust estimates of air quality come to us from the thousands of monitoring stations that the EPA maintains across the country. And usually those estimates tend to be gathered on a daily basis. So that's the way we're doing it now. So what are you doing here? How do you think Twitter can improve our air quality forecasting? So what we found in two consecutive studies is actually the frequency with which users post content about wildfire and specifically wildfire and smoke tends to be a pretty good estimator of air quality impacts in the region surrounding wildfires and gives us a pretty dynamic real-time estimate of how smoke is moving across a region.

How did you think to do this? Well, there have actually been a lot of researchers mostly in China who have used WIBO, which is, I think, a Chinese version of Twitter, are a pretty good, similar version of that. And they've been using WIBO to look at whether posts on WIBO can actually estimate air quality, you know, independent of wildfires in China. And they've found that, you know, in the absence of monitoring stations, or reliable data for monitoring stations there, WIBO posts can actually be a good estimator.

Can you get a sense of what people are thinking about a fire from their tweets, about how concerned they are for their safety, how close the fire might be, that sort of thing? Yeah, and as social scientists, that was actually one of the most interesting aspects of this project for my co-author, Sarah McCaffrey, and I. We were able to build a conceptual model of how people are actually reacting to,

and adapting to wildfire smoke in their regions. When people express something about a fire, obviously there's a lot of fear probably. I'm wondering how their opinions, as communicated on social media, could be viewed as interesting data, but maybe they can help you predict a little bit more. Tell me more about the content. Tell me more about the content that people are actually providing in these tweets.

Yeah, and it's interesting that you bring up the fear. That was actually a topic we did not see emerging in the automated text analysis that we did of these tweets. What we saw was people were obviously very concerned about their air quality impact. So, you know, there would be a lot of tweets about, I can't breathe today. The air is thick with smoke. And what we found was that when we added that semantic content into our predictor models of air quality, we were actually able to increase by about 50% the predictive power of our models.

In addition to those topics about smoke and air quality, we also saw that people were tweeting about, you know, offering their gratitude and thanks to the firefighters who are putting themselves in harm's way. They were also really concerned about their own safety and asking the world to pray for them. And especially with some of the more recent fires like the car fire, I have once again seen that those types of topics emerge. We had asked our listeners to tweet us about what they're seeing. Bonnie on Twitter said it's a little smoky in Reno, Nevada today from the Ferguson fire near Yosemite. We're getting forecasts for smoke along with our local weather forecasts. What she's telling me is the wildfire smoke is traveling quite a way. Reno's not real close to Yosemite.

Oh, yeah. Yeah, I mean, you're seeing some of the smoke go a long way. Hundreds of miles, in fact. And actually one analysis that I saw that was done by. by the NRDC suggests that about two-thirds of the counties in the U.S. are affected by wildfire smoke to some extent. That's amazing. What you did here is an analysis of tweets kind of after the fact.

Is this something that's almost ready to go? I mean, could you use this in real time in some way? That is our eventual goal. And right now, one of the biggest problems that we see with that is in order to get the most high-quality tweets, we have. have to rely on the hashtags, right? So like it's hashtag Carfire, hashtag Ferguson fire. And those tend to give us, you know, tweets glean on those keywords tend to give us the highest

quality tweets. But of course, if you're building something like this in real time, you can't really rely on those hashtags because in a lot of cases they haven't even been developed yet. So we're trying to figure out what are the best keywords to give us some of those really high quality data points. But I'm wondering, I mean, here you are on the national. radio program and you're telling people about this, is there a way to get people to think about Twitter as a way to help you get information? Like if everyone use the hashtag and everyone

gave you certain types of information about their location and the type of smoke they were seeing, you might get a lot more data than you ever had before. That is an excellent point. And we are hoping to work with local managers in promoting those types of norms. And actually, it's funny that you mentioned it, but just this morning I was on Twitter and I was looking at some of the posts around the car fire. And I noticed that there were users policing other users and asking them not to conflate multiple fires in a single post. And I found that to be so interesting that, you know, these norms are kind of evolving and are being self-policed by users on Twitter. How much do you have to sort of cancel out the noise, though, that you get with any sorts of large

information coming from sources that might not be reliable. I think of myself as a news person who uses Twitter a lot, but every time there's a breaking news story, you have to look at things with a little bit of a grain of salt. Is there a lot of data that you're getting that maybe isn't all that useful? Yes. As with any data source, as you pointed out, there's going to be some level of noise. And with social media sources, just because, you know, we're reaching millions of people, there might be a lot more noise. And there is an intensive data cleaning process that we go through. And as we're building a real-time monitoring system for fire,

that is something that we have to be very aware of. There's a couple of other sources that are out there right now. There's an account on Twitter at Wildfire Signal, and the EPA has an app called SmokeSense. Can you tell us about those and how they might interact with some of the work that you're doing? Yeah, I think it's a really great time to be using social media data and basically just crowdsourced data as a whole in all of these multifaceted ways to target the specific issue. In terms of the Twitter bot wildfire signal, it's a little bit different than what we're doing because what Descartes has actually done is they identify active fires on the basis of a governmental database. and then they use a satellite to take pictures of where the smoke is coming.

So it's kind of a more distant perspective on how smoke is traveling. And SmokeSense, as you mentioned, the app by EPA is another great example of bi-directional communication that can be done via the use of smartphones. However, they're not really able to harness social media conversations, which tend to be much more prolific than using. users of a particular app. Wildfires seem to just be getting worse. Is this something that in the next couple years you think you can operationalize at a higher

level than you are right now? Yeah, we're definitely hoping to scale this project out, you know, not just in the U.S., but wildfires are becoming a global concern or have been a global concern. And particularly in regions where monitoring stations are sparse, but social media use is widespread. We're hoping this could be a really influential tool. Sonia Sceada is a research social scientist with the U.S. Forest Service Northern Research Station in Chicago. Thank you so much for joining me. I really appreciate it. Thank you. So what do wildfire smoke and dust from the Saharan Desert have in common? Well, earlier this month,

a cloud of dust came rolling into the atmosphere above Texas and the Gulf Coast. It was a remnant of a dust storm blown over from the Saharan Desert. And like the smoky conditions in the west, the dust is impacted air quality and breathing conditions for people living in the haze. But according to a new study in the Journal of Climate, that Saharan Dust also brings with it a silver lining. It suppresses the formation of major storms. In fact, my next guest says an especially dusty atmosphere is a strong indicator of a less severe hurricane season. Bowen Pan is a postdoc research associate in the Department of Atmospheric Sciences at Texas A&M University. And Bowen, welcome to Science Friday. Thanks so much for being here. Thank you so much for inviting me, John. I'm wondering if you can just start with the

most obvious question people will have. How exactly did dust from the Sahara Desert and Africa make it all the way over to the U.S.? So first, when the dust at the Saharan Desert, when there's a strong surface wind, when the surface wind is exceeding a certain threshold, the dust can emit it from the surface towards the mid-laden, like meat atmosphere. So it can reach as high as several kilometer high. And then this does going to follow the trade wind from the Azores High. So it's blowing from the West African towards the United States. It's going to follow the trade wind across the North Atlantic Ocean and reaching the U.S. That's normally how to get there. So that's how it happens. And is this happening a lot? Is it happening more often?

I think for this year it happening more often than before. And then I think the Azoor high is much stronger than before. That's why we have a much stronger trade wind. So that's why we have those more frequent dust outflow into the Houston region. Yes. So the dust gets blown up into the atmosphere. How long exactly does it take it to get here to say Houston? So normally it take about seven to 10 days to just travel from the West African to Houston region. And it also can take about 13 days just travel around the globe. It can travel really far away. And since it's being blown by the winds, I'm not sure. Is it blowing across and then leaving quickly, or is it lingering over one part of the country? It really depends on the local meteorology condition. So if the wind is not strong enough,

so the dust can stay in certain region for a long time. But normally it travels from across the Atlantic Ocean, it can be pretty fast since the trade wind is pretty strong over there. Okay, so let's get into how it might suppress storms. I guess I always thought that particles in the air made it more likely clouds would form and clouds would lead to rain. So why would all this dust in the atmosphere make the storms less likely? Yeah, I'm glad you brought it up. And actually, dust can have two different impacts on the storms.

So the one you're talking about is dust can play a role in cloud formation. So we call it microfysical effect. But here in my study, I'm looking more of a radiative effect. So the dust is absorbing and reflecting sunlight. So that's how it kind of increasing the temperature in the atmosphere, but decreasing the temperature at the sea surface level. So it kind of stabilized the atmosphere. That's why we have more of a suppress hurricane condition when we have more dust outflow. So this dust is hanging at a place in the atmosphere.

Explain about how far off the Earth's surface this is traveling? So normally it's in about two kilometers high above the sea surface. So normally around the sea surface area, we have relatively colder temperature. And then about that high level, we have a relatively warmer temperature over there. And then it can travel like thousands of kilometers just to reaching the U.S. I'm John Dankovsky, and this is Science Friday from WNYC Studios. And we're talking with Bowen Pan, a PhD candidate in the Department of Atmospheric Sciences at Texas A&M University about how dust from the Sahara might be causing interesting climatic conditions here in the United States.

So remind us again how storms work. If we're talking about a major storm like a hurricane, where does the storm get its energy from? So normally the storm form as a cluster of thunderstorm off from the West African coast. So we call it African-Easley wave. So about 40% or more than 50% of the hurricane in the Atlantic Ocean as forming from the cluster. of thunderstorms. So this thunderstorm move towards a warmer sea surface temperature, so normally warmer than 80 degrees Fahrenheit.

So it gets the energy from the sea surface. So it caused by like evaporation and a latent heat release. That's when the hurricane really, or the storms really build up vertically and form a hurricane there. So then the dust does what? The dust acts like a kind of a window shade. It keeps down the amount of heat that's being used as fuel for the storm? Yes, and sort of like that.

This does reflect and absorb sunlight, so it kind of warm up in the mid-atmosphere and then cool down the sea surface. So kind of troking the storm to build up vertically, basically. Are there some examples where we've seen this, times at which there was a lot of dust activity and it coincided with hurricane season? Yes, I'm glad you bring this up. So for our study, we're looking at the year of 2005 and 2006. So when we are at the year of 2005, that's when we have those really catastrophic Hurricane Katrina at that time. So we have more 20 plus hurricanes at that year. And then so for the year of 2006, the National Hurricane Center kind of predict above average hurricane season, so relatively active.

But in the end, in 2006, we only have about 10 hurricanes at that time. So researchers are wondering what is the cost of it. And then we see that the Saharan dust advances more frequent in the year of 2006, which kind of decreasing the sea surface temperature at that time and then suppress the hurricane season at the year of 2006. So 2005 is a terrible hurricane season. We predict another one in 2006, but then there's a big dust storm, and you're saying that's what tamped down the hurricanes in the following year.

Yes. Well, so with all of this, is the evidence you're strong enough that forecasters should start to put this data into their models where if there's a lot of dust coming from the Sahara, that might mean, well, we won't have as bad a hurricanes as we're expecting. Yeah, it's actually a really active research field right now. So the prediction of Saharan dust events is kind of challenging right now. But taking into account the Saharan dust events, it's definitely going to help us to make a better prediction of the hurricane season in the following year. But you say it's kind of hard to predict the Saharan dust storms.

Now, why is that? We've got these models that show when hurricanes are forming in the Atlantic and coming toward the United States. Why don't we know more about the dust events that are happening in the Sahara? Yeah. So when we are doing the prediction of Saharan dust events, we need more detail of the surface texture. So right now, I think this data is still limited from a certain resolution.

So it's still coarse resolution right now. And then we also need to predict the surface wind correctly, but still a challenging topic in our field. So that's why the prediction of Sahara's events is kind of challenging and heated topic right now. It's a very interesting topic as well. Thanks so much for bringing it to his Bowen Pan, as Postdoc Research Associated in the Department of Atmospheric Sciences at Texas A&M University. Thanks for joining us. Thank you very much. After the break, Mars has a hidden lake under its ice cap.

Find out more right after this. This is Science Friday. I'm John Dankoski. The search for water on Mars has been going on since the 1970s. So far, we found frozen water on the ice caps of Mars. Trace amounts locked up in Martian soil, but nothing liquid. That is until this week. Scientists from Italy's National Institute of Astrophysics announced that they found liquid water underneath the ice caps on the South Pole. It's not just a little bit of water either. It's a lake about 12 miles wide. So what it means for human missions to Mars and future Martian water research. Well, here to tell us more about that discovery is Anheh Aboud Madrid. He wasn't on the study, but he's the director of the Center for Space Resources at the Colorado School of Mines. Anheel, welcome to Science Friday. Thanks for being here. Hello, John. How are you? I'm doing quite well, and I'm interested to talk with you about this. Our listeners might have some questions, too. So if you have questions about water on Mars, you can call us 844-7-24-8-255. That's 844-Sci Talk, or you can always tweet us at SciFri.

So this isn't the first time we found water on Mars, but there's something big and different about this discovery. Tell us what's so interesting about this. Well, the exciting thing about this announcement is the first time that liquid water has been found on Mars. As you mentioned, water has been found as ice on the subsurface, very close to the surface with the Phoenix lander, and also one to two meters were discovered

and was announced earlier this year, has also been found. water vapor on the atmosphere of Mars in very low quantities. And water is also trapped on the minerals. But this is the very first time that liquid, a body of liquid water, has been found. Isn't the South Pole of Mars really, really cold? I mean, how come this underground lake is completely frozen? That's a good point.

It's a really cold region. You can get down to minus 120 degrees Celsius down there. But think about this body of liquid as putting some animal. freeze on that. Not only the pressure of the ice cup on top of that, which is about a one and a half kilometers, lowers the melting point, but also this water appears to be combining with salts of magnesium and sodium and calcium. So it's salty waters. Think about it as a brine. And so that can lower the melting point and it can exist in the liquid phase. How do the researchers know that this water water is salty? Is it just presumed because it's not frozen? Or there are other ways to tell?

about the contents of this water? That's one thing, but the other one is that it may be combined with some of the soil material that is found in those regions, and they're known to have this type of components, and they have been found on other places on Mars. So that's the theory. Plus, in order to exist at that very low temperature, which is supposed to be around minus 60, minus 70 degrees Celsius, definitely it needs those type of materials in order to lower the melting point. There is liquid water under the pole, say, in Antarctica. Is it similar to that?

Is it similar to what we see here on Earth? Exactly, yeah. And in fact, scientists from that mission use some of that data to calibrate their instrument. The instrument up there can receive signals and they can indicate water, but in fact, they can be compared to what was found in Antarctica, which is very similar when you find bodies of water, of liquid water below kilometers of ice. So it corresponds very nicely to what it was found on Mars. You mentioned the equipment they're using.

What exactly did they use? How did they discover this on Mars? The Mars Express spacecraft from the European Space Agency has been flying around Mars for almost 15 years now. And it carries on board an instrument called Marsis, that it's an acronym for Mars advanced radar for subsurface and ionosphere sounding, a complicated name. But as the name says, it has a radar, the same type of instrument one uses on control towers to look for airplanes or for submarines or ships. This one happens to be a ground penetrator and radar. And as the name says, the signals electromagnetic waves that come up from this instrument can bounce. on the surface of Mars, providing a way to look at how the topography of the terrain is,

sort of like an altimeter. But those sound waves, those electromagnetic waves can actually penetrate through the surface. And as they go through that, they can distinguish between different types of layers. If it is bedrock, the signal that bounces back will be different from ice, will be different from water. and so by looking at the reflection, the magnitude of the reflection, how bright it looks on the instrument, you can tell what type of medium is that. And this team has been extremely resourceful and very persistent.

For three years, they have been looking at the signals, making sure that they can correlate with the signal of water, and that's what they announced just yesterday. How deep is this pool of water, do they think? They seem to think it's about a one and a half kilometers. This instrument has accessed in a lower frequency. That means it can penetrate to kilometers. And they saw the signal bouncing from about one and a half kilometers. And they measured the depth of this lake, which is a very shallow lake.

It's about a one meter. So it's a very, it's like a, it's not really a lake. It's just a pool of water of one meter. But it's like you said, 20 kilometers. meters across, so it's significant. Okay, so it's pretty far down there, but then it's only a pretty shallow pond once you get all the way to the water. Correct. I want to get to a phone call. Austin is calling from Casper, Wyoming. Go ahead, Austin. What's on your mind? Hey, I was just wondering, what are the chances of getting any water samples from Mars back to Earth in

the near future? And would it be more cost-effective to study those samples on site rather than ship them back and have a study them here. Great, great questions. Anhele, what do you think? Absolutely. Sending anything to Mars is extremely not only costly, but it's very energy-intensive. Getting down to the surface, drilling, that is a very difficult thing to do. But there is a mission that will actually, is being planned to bring samples to Earth,

not necessarily of water. This will be of soil that is found on Mars. Some of it, by the way, that have some water contact. The regular soil that is found on Mars on the surface has about 1 to 2% of water. Some of it, think about Jepsen, has up to 20% of water. So these are actually places when we can find the water if you just heat them up. But actually getting water, the one that was discovered earlier this year is about 1 to 2 meters. So that's a reasonable depth to drill, find the water,

on-site, measure it there, and then send the signal back to Earth without having to bring it. And you can, I mean, they were able to find out that it was water. Why not just drilling, obtaining it there? They can measure the composition and send a signal back to Earth without having to bring it all the way down here. Because this is an awful lot of water in this lake, what do you think it tells us about other water on Mars? You've already explained how you can find water in the rocks or in different other parts of the planet. but does it tell you that there's much more water somewhere that we just haven't found? Oh, absolutely. I mean, this may seem like a big lake, but the subsurface ice that was found earlier this year, this is comparable to Lake Superior, basically.

So there's plenty of water ice. The one that was found, or what was announced yesterday, is liquid water, but water ice, it's, I mean, you can see it on the, on the polar, on the poles, the ice cap. there's vast amounts of water ice. It's just that the one that was found was liquid, but you can find water ice subsurface in very, very large quantities. Now, whenever water is found someplace like Mars, people immediately jump to, well, does this mean that there's life there? But you're really fascinated by this water for other reasons. What do you want to know personally in your research about this water?

You're exactly right, John. Every time it's great to find water on Mars, no matter how you find it. Most of the times it's for scientific reason. It's good to know where the water is, how it evolved from a wet planet to what it is now dry. Where did the water went? So what will go?

So it's an important thing to find that scientifically. Life is another reason why we should be excited about this because there may be microorganisms that were preserved on this liquid water. But as far as I'm concerned, and for my colleagues at the Center for Spade Resources at the Colorado School Mines, as the name of our center says, we are interested on water as a resource, something that can be utilized for missions where humans will once will have a base on the surface of Mars. Anything that we can use from Mars that cut our dependence from Earth,

which is extending anything from Earth is extremely energy-intensive, extremely costly, and so utilizing anything from Mars will be very useful. Also, recycling whatever the crew is going to use there. But water, the importance of having water on Mars is obviously for human use, for drinking, for growing plants, for shielding them against radiation. But the most important use is that you can split water into hydrogen and oxygen, the most energetic propellant that has been found that actually is used on rockets. Also, water can react directly with the carbon dioxide of the atmosphere

and combined to give us methane and oxygen, also a very powerful propellant. And the use of that is that you can use it for a vehicle that will actually bring the crew back. So you don't have to take all that fuel all the way to Mars so that they can come back and that will make it more cost-effective and also use less amount of energy. So you're really interested in this as potential rocket fuel making something that's going to get people either further out into space or back from Mars once they get there? Right. I mean, you can use the propellant to even have a hopper. I mean, you can go from one place on Mars to the other one, the fuel to bring you back. And yes, you can probably at some point use it to propel you to other places in the solar system. Sean tweets at us.

Do you think that this discovery will drive renewed interests in attempting a Mars trek? Because, you know, the American Space Program has gone back and forth about where we're going to go next and whether or not Mars is on our radar. So do you think finding water, a big lake like this on Mars, is going to excite people to go back? Yes. In fact, NASA is quite excited about this. Two years ago, he had a big meeting looking at possible landing sites. for humans. And this will be a base that will hold four to five crew, four to five persons that will be visited repeatedly. And one of the important things that NASA is looking at,

what is the optimum site, not just for scientific purposes, you know, where it's something that a place that is very geologically interesting, but that will have the resources to keep the crew there. And I think NASA is realizing that using the resources from the planet will be a if we want to have humans there. And the purpose is to have humans in the next, I don't know, 15 to 20 years, and they will be using definitely the resources on Mars. So having an announcement like this is quite exciting. Obviously, it all depends where the water is.

It's all about location, location, location. This discovery was done at a very high latitude, about 81 degrees south. And so these are places that are extremely cold, very long winters, maybe not ideal for a human base. But the discoveries of water ice at lower latitudes are quite exciting because the water is just a couple of meters down. And so you can extract it from the ice and have it ready for a Mars base. I have to say you do sound excited about it. Anul Anul Abud Madrid is from the Center for Space Resources at the Colorado School of Mines. Thank you so much for talking with us about it.

I really appreciate it. Thank you so much, John. I'm John Dankoski, and this is Science Friday from WNYC Studios. Now, if you want to see Mars ice caps yourself, you can get a glimpse tonight. The dusty red planet will be the closest it's been to Earth in 15 years. To talk about the best ways to spot the planet is Bonnie Minkie. She's a project scientist at NASA's James Webb Space Telescope. Bonnie, welcome to the show.

Hello. Nice to be here. This is the closest Mars has been to us in nearly two decades. Why is it so close right now? Well, it's in opposition, which means that if you were to draw a line from Mars to the sun, it would intersect the Earth. So we are at the best location in the Martian and Earth year, where they both align, and they're the closest to each other that they will be. Now, why it happens closest in the 15 years is because they're on circuptu. orbits, but those circular orbits don't quite overlap at the very center of those orbits. So

the Earth is a little bit farther out, and Mars is a little bit closer in. So that perfect alignment just happens this weekend. If I go outside to look for Mars, where exactly should I be looking tonight? You're going to want to look to the southern sky. You will see a big, bright, pretty full moon, and you'll look just to the south of it and a little bit to the south of it, and a little bit to the right as you're facing south. You should see a nice red spot of light that doesn't twinkle. That's how you can tell it's a planet. And that is Mars. You might see another bright non-twinkling spot of light, and that will be Saturn a little bit farther to your right. Now, with the naked eye, I'll be able to see it maybe a bit brighter than usual. But if I'm

using, I don't know, just binoculars or a cheap telescope, what will I be able to see? Oh, that's really exciting. So you can take those outside and you'll be able to see some of the poles. Right now, Mars is in a global dust storm. So what you're going to see is a little bit of white at the top, a little bit of white at the bottom, and everything else will be a kind of orange color from that dust storm. But you'll definitely be able to pick out the polar ice caps. So dust storms, you'll actually be able to see them.

What will that look like? Does it make Mars all fuzzy? It does. It's funny. We've seen dust storms every few years, something like six to eight years, we see these global dust storms erupt on Mars. And every time it covers up all of the big interesting features on Mars. But the dust storm itself, while fuzzy, is very interesting for us because it means that we're tracking weather over time. As you track weather over time, you get to learn a little bit more about climate. So we're, we're, we're, we're, we're, we're, we're, we're, we're, we're, we're, we're, We're becoming weather meteorologists for other planets in our solar system. And NASA released new photos of Mars with these dust storms. Is there some really great detail in there? There is. So the Hubble Space Telescope looked at Mars last week to check out this global dust storm.

You can still see some surface features because it's Hubble and it has really good resolution. You see a little bit of dark spots on the surface from canyons and other features. But really, the thing to watch for are these dust storms and how they are moving and changing. It's remarkable to compare them with previous years. So if you look at, say, 2016, where there wasn't a dust storm, you can see what a difference this makes and how it really takes over the entire globe. Oh, we're excited to take a look. As a matter of fact, we've got those NASA photos of the dust storm.

on Mars. Up at our website, science Friday.com slash Mars Dust. Thanks so much, Bonnie. I really appreciate your time. Yes, it was great talking with you. B.J. Leatherman composed the theme music for our show. And if you missed any part of this program, or you'd like to hear it again, subscribe to our podcasts. If you've got a smart speaker, ask it to play Science Friday wherever you want. Every day is now Science Friday. You can always find us on Facebook, Twitter, and Instagram. You can email us SciFri at ScienceFri.com. Send feedback. us what you'd like to cover too. Happy Mars hunting tonight. I was back in the host's chair next week and I'm John Dankosky in New York.