From Earth orbit to the Moon and Mars, explore the world of human spaceflight with NASA each week on the official podcast of the Johnson Space Center in Houston, Texas. Listen to in-depth conversations with the astronauts, scientists and engineers who make it possible.
On episode 359, a NASA astrobiology program scientist discusses looking for signs of life beyond us in the stars, and the study of the origin, evolution, and distribution of life in the universe. This episode was recorded on Sept. 18, 2024.
Transcript
Host (Dane Turner): Houston, we have a podcast! Welcome to the official podcast of the NASA Johnson Space Center, Episode 359, “Astrobiology.” I’m Dane Turner and I’ll be your host today. On this podcast, we bring in the experts, scientists, engineers, and astronauts, all to let you know what’s going on in the world of human spaceflight and more. On this episode, we’ll discuss aliens of little green men. Well, not exactly, but the subject of life somewhere among the stars is something that powerfully captures the human imagination. More so than that, there’s a scientific field that looks at life in the stars.
The study of the origin, evolution, and distribution of life in the universe, astrobiology, is a complex and nuanced field. We won’t be necessarily discussing extraterrestrials directly today, but we will be talking about the signs that we’re looking for that help show that maybe we aren’t alone in the universe. To help us on this journey, we have Becky McCauley Rench, a program scientist in the Planetary Science Division at NASA Headquarters. She’s the acting program scientist for the Astrobiology Program and leads the Habitable Worlds Program, which we’ll be discussing more later. So watch the skies and let’s look for signs of life.
[Music]
Host: Hi Becky, and welcome to Houston We Have a Podcast.
Becky McCauley Rench: Thanks so much for having me. I’m really excited to be here talking to you today, Dane.
Host: So you’re the acting program scientist for the Astrobiology Program, and you lead the Habitable Worlds Program. So how did you get to where you are today?
Becky McCauley Rench: Oh, wow. So that’s a story for sure. It’s not exactly where I thought I was going to be growing up. I mean, I was always interested in space, but I guess I thought I’d be an astronaut rather than a program scientist at NASA Headquarters. But I guess it really started, you know, as a kid. I loved space. I grew up in West Virginia where it’s nice, clear skies. So I spent a lot of time looking at the stars, very interested in the Earth and the environment. Was a big fan of Captain Planet and like saving the Earth. And I kind of continued that love of science through high school when I did an internship with NASA through the IBMV Center that’s in Fairmont, West Virginia. It’s an offshoot of Goddard. And I spent the summer there in high school with this astrophysicist at West Virginia University through that internship, just looking through a telescope and looking at Mars and researching about Mars. And I came across a NASA scientist, Chris McKay, Dr. Chris McKay, and the work that he was doing in astrobiology and kind of thinking about life and extreme environments. And I got hooked right away to that I thought this is like the coolest science anyone could ever do. And so from that point on, I knew I wanted to be an astrobiologist. And so I went to West Virginia University for my undergrad. And I was the first person in my family to go to college, and so I didn’t really know what college was. And so I was like, oh, I’m just going to go to college and I’m going to become a scientist. And it was there that I found out that there were all of these levels to college that it wasn’t just college, that there was undergraduate education and master’s level education and graduate education. I had a lot of professors really take me under their wings and help guide me.
And so I basically ate all the different science I could, biology, chemistry, geology. And after undergrad I went and I did an internship at NASA again, this time at Goddard with the Mars Science Laboratory team, cause that hadn’t launched yet. And so I spent the summer working with that team at Goddard, learning about this instrument called SAM, which was the Sample Analysis at Mars. It’s an instrument that they were going to take samples and heat them up and see what sort of organic molecules came off of these rocks at Mars.
And so, you know, I kind of continued on that path and went to graduate school, my PhD in astrobiology and geosciences, and then pretty much straight out of grad school I knew I wanted to mix policy and science in some sort of way. So I headed to Washington, D.C., where I figured all of that would be happening. And I was lucky enough to get hired on relatively soon at NASA Headquarters onto the policy team. And so, I spent several years doing policy work for NASA. And then in the past five years or so, I moved over to the Planetary Science Division and got back to my roots in astrobiology and have been, you know, working there ever since. So I’ve been at NASA Headquarters for about eight years now doing program level work to enable science throughout the U.S.
Host: Wow, that’s one heck of a path to get here.
[Laughs]
Host: So how would you describe what you do to someone with no knowledge of what planetary science is?
Becky McCauley Rench: Yeah, so, you know, it’s kind of funny because I didn’t call myself a planetary scientist until I got to NASA Headquarters. Before that I called myself an astrobiologist or a geomicrobiologist interested in Mars, pretty much at all points in time. So describe planetary science to other people. It’s learning about all of the bodies in our solar system. They’re all different and they have things to tell us about solar systems and planetary processes. And you go all the way from giant planets like Jupiter to small bodies like Arrokoth in the Kuiper Belt. And then you have, you know, Earth is even in there. It’s one of, I think, the most unique planets in our solar system cause it has life. It has a biosphere. It makes it one of the most unique and interesting places in our solar system. And that’s really what, you know, I want to learn. I want to learn about life in the universe. How did our Earth become this planet bustling with life? And, you know, is that something that exists anywhere else in the universe?
Host: I think that’s a great goal to learn about. And is that the aim of astrobiology? What really is astrobiology?
Becky McCauley Rench: Yeah. So astrobiology is study of the distribution of life in the universe. So it’s not just the search for life. In reality, it’s much bigger than that. Astrobiology is done here on Earth, actually, where we have life. And so we’re not really searching for life on Earth. We’ve already found it. We know it’s here. What we want to do is we want to understand how did that happen? How did you go from a world that was abiotic, so something that didn’t have life on it, but that maybe had the right environment and building blocks for life to something that has a biosphere and abundant life. Does it have to be a planet like Earth, or can it be something different like the ocean worlds that we see in the outer solar system? So something where maybe the planet itself is kind of in a colder place in a solar system, but there’s this awesome energy source, maybe deep down, and then ocean that could also be someplace where life maybe originates from or can thrive in. And then also exoplanets. So looking for life and trying to understand whether or not other solar systems out there maybe have life or have habitability. It’s also this question of, does a planet habitable always have life, right? Or can you have habitable planets without life? And what does that mean? So it’s everything from trying to understand that origin, right? Moving from prebiotic chemistry to biotic chemistry to all of the ways life finds how it can survive in different environments. What makes a planet habitable? And how many habitable worlds are there out there? How many worlds are there with life? Whether that’s just, you know, little microbes or something else.
Host: Okay. So I have to ask, does this mean that we’re looking for aliens?
Becky McCauley Rench: Well, yes, we are. We are looking for aliens, maybe not in the same way that pop culture, you think of them, so not little green men, not, you know, spaceships bustling around. Really, what we’re looking for are those signs of microbial life. And the reason for that is because we have one example of life, and that is Earth. And whenever you look at the life on Earth, microbial life is really what is expansive and able to survive and find a way to make a living in a variety of environments. And so it seems like the best option to search for life anywhere else. It’s the most probable thing to survive in the subsurface of Mars or in an ocean on Europa or around some other exoplanet.
Host: This is absolutely fascinating. So can you tell me a little bit more about the history of the field of astrobiology? How long have we been doing this?
Becky McCauley Rench: Yeah, well, you know, so I tell people that we’ve been asking the questions of astrobiology since the beginning of human thought. So, you know, very long time, the questions have been in the human psyche, but really in terms of a science, you know, sometime in the 1950s, 1960s, you start to see this word exobiology show up in the lexicon. And those scientists were, I don’t even know if they would’ve called themselves planetary scientists, really. You know, at that point in time, most of those folks were Earth scientists that were trying to take their disciplines and apply it to other worlds. And they were interested in this, you know, possibility of life elsewhere. They really had no idea what Mars or Venus or, you know, they didn’t even know about many of these moons in the outer solar system that we think of today. So it was really new to them.
Then we had, so we had, you know, in the 1950s, 1960s, and then in the 1970s, we actually had the Viking mission. So that was 1976. And that probably the mission that I would say, like looking at all of NASA’s missions, it was like the most direct we are searching for life. This is astrobiology very clearly no other big goals for that mission. So really, Viking went to Mars. It was the first U.S. landing on the surface of Mars. And it was there to search for life. It had these biological experiments. And what it ended up doing was teaching us that we had a lot more to learn at Earth. That we didn’t have a full understanding of what it really meant to be life. So we took kind of a step back for a period of time, I think.‘90s we started learning. 1980s, 1990s, we started to explore more places on Earth. You know, I tell people, you know, I was in elementary school whenever we didn’t even realize that there were microbes that lived in the deep-sea sediments. There’s like all of these places on Earth that we had yet to explore and find life. And we found them, right? We started to go to these places and really gain a better understanding of understanding what life on Earth was like to inform our search for life and our astrobiology research elsewhere. And so then we found out that water and organics were kind of common in the solar system. We had some reinvigoration of the field in 1996 when the Allan Hills meteorite, ALH84001 ended up in the media and on the, you know, the president’s lips. And so, you know, while that ended up not being something that we actually think was any sort of indicator of life, there were thoughts that maybe it did have something. And so that reinvigorated this field of astrobiology.
And so in the 2000s, we ended up working on MSL, the Mars Science Laboratory, and thinking about Mars sample return. And so those missions kind of got started in the early 2000s. And then we’re at where we are today in there was also a discovery of exoplanets through both indirect and direct observations, more science of the outer solar system, which gave us this idea of ocean worlds and these deep-sea environments that could also be habitable. So there were a lot of things that happened there, especially in the 1990s and early 2000s.
Host: This is a really storied history. So you mentioned Viking there, and what are some of the other tools and missions that have contributed to our current knowledge?
Becky McCauley Rench: Oh, so the list goes on, start with thinking about terrestrial planets, right? So Earth has life, alright, check that box. We also have Venus and Mars. And so, you know, we had Mariner 4 that went by Mars, and that gave us our first fly by and some knowledge that there must have been some things flowing on the surface, which then led us to Viking. We also had Pioneer, which went to Venus. And I would say for the most part, what that did was made us realize how hostile Venus was, that it wasn’t necessarily as similar to Earth as we may have thought it was. And so kind of pushed our focus back to Mars. And then at Mars, we’ve been going right with the Mars exploration rovers, MSL, now, Perseverance and Mars sample return. We’ve been able to complete this whole story of water and habitability and, you know, trying to bring samples back so we can understand the potential. Like were there any biosignatures any signs of ancient life? What’s the history there? All of those missions have made it so that we know Mars was once habitable, which is really interesting, that we don’t see any evidence right now on the surface of life. And so if there is any life there or any signs of life, it’s going to be ancient, maybe back in whenever the surface was habitable or it’s going to be something in the subsurface. And so that’s where we want to look in the future. So that’s kind of Mars.
About the ocean worlds, some of the missions that were really important were Galileo and Cassini going to Jupiter and Saturn. So these, you know, kind of brought to the forefront these moons like Europa and Titan and Enceladus that have just very interesting chemistry going on, right? So we know that there’s a lot of organics out there. Titan has methane lakes, which are really interesting from a prebiotic chemistry standpoint. Ad then Europa, we think has these subsurface oceans and these worlds, you know, we talk about them as moons, but they’re really big for the most part. They’re definitely planet sized bodies in the solar system, right? You know, they’re moons of these giant planets, but they’re very comparable in size to the terrestrial planets like Mars and Venus and Earth. So that really opened that bucket, right? Where we realized we couldn’t just think about terrestrial planets. We also needed to think about the older outer solar system and these ocean worlds and what we could learn out there, whether search for life or just understanding prebiotic chemistry. And like I said, how do you move from being a prebiotic, abiotic world to, and there’s the exoplanets, right? We’ve had Kepler and we’ve had TESS and we’ve had Hubble and James Webb have really significantly increased our knowledge and just the quantity of exoplanets that are out there. And our understanding that the way that our solar system looks is not necessarily the way that every solar system looks with these small worlds in close to the Sun and these bigger planets out in the outer solar system. There’s this whole diversity of exoplanets out there and what that opens up in terms of potential habitability and the search for life. And then I’ll also just mention that there’s also OSIRIS-REx and missions like Stardust that have also looked at these primitive bodies in our solar system and helped us understand the organic chemistry that would’ve existed in the early solar system, all of that delivery to Earth and what that might’ve meant for life originating on Earth. So there’s a ton there in those missions and what they’ve been able to tell us and how that’s driven us forward in our understanding of astrobiology.
Host: There’s a lot diversity in the missions here. So you mentioned exoplanets and, you know, those are outside of our solar system, and even our best telescopes right now still make stars look like colorful pinpoints. And so how do we see planets and how do we identify the potential for a habitable world when we’re looking at something that is smaller than these pinpoints on in the images we get?
Becky McCauley Rench: Yeah. So I’m not an astrophysicist, but I work with them. And they’re amazing. And they have a lot of amazing tools in their toolbox to help them get as much data as they can out of these photons that they get with telescopes. And that’s both ground-based and space-based telescopes that they’re able to do this with. So they can do indirect measurements of exoplanets, so they can look at stars and they can see how a planet tugs on the star to move it. And that can tell them something about that, that planet. They can see the dip in the stars luminosity. So that dip is because a planet moved in front of it, right? So those are like indirect measurements, and then they can do these awesome things with chronographs or anything that you’re going to do to kind of block out the main source of light so that you can see the fainter objects around that. And that’s how they can do some direct imaging of exoplanets. So they’re really good about figuring out the exact physical dimensions that you need to block out from the main star so that you can see the things around it. And they do that with chronographs. They can also do it with things like star shapes that they can put out. We haven’t never done that. Chronographs are easier to fly, but there’s tools to do this. And then they do the same thing with ground-based telescopes, right? You can do chronographs. And then there’s also AI and the amount of computer coding that can go into this that can help identify these things as well by just looking at very large datasets and finding candidate exoplanets as well.
Host: That is incredible. I didn’t know there were so many tools that they could use to discover these things. And they can also do is it spectroscopy to kind of figure out the chemical makeup of some of these stars and worlds and stuff?
Becky McCauley Rench: Yes, they can. So they’re getting back those photons from the exoplanets that they’re looking at, and they can look at the spectra of those photons and they can look for these wiggly lines basically. And by looking at the peaks and the troughs and the distribution of that, they can make observations about the potential chemistry that they’re seeing, likely in the atmosphere or something like that. But yeah, it’s totally possible. And actually that’s one of the things that we really want to do with a Habitable Worlds Observatory. So that’s not a mission that is flown yet. It’s a mission that’s very new in its ideas but hopefully would be one of the next great observatories out in the late 2030s. And it would be able to do exactly that. It would be able to give you some idea about the atmosphere on these exoplanets that is able to directly image.
Host: Fantastic. And we’re going to ask you a little bit more about the Habitable Worlds Observatory in a little bit. But when we’re talking about the spectroscopy here, are there specific chemicals or special signs or markers we’re looking for?
Becky McCauley Rench: So yes, there are definitely special signatures we’re looking for. So whenever we think about searching for habitability, what we do is we start at home. So I mentioned before we have N-of-1: Earth; but it’s actually a little bit more than N-of-1. It’s like N-of-1.5, because we have the whole history of Earth and we have access to the rock record on Earth that tells us about the Earth’s environment over the past four billion years or so. And most of that time there’s been life here, and it hasn’t necessarily looked like it does today. It’s looked like a lot of different planets. And, you know, we know all of those planets had life, right? So all of those versions of Earth throughout its history had life. And so what we can do is we can look for similar signatures that we would have expected to have seen from Earth around those exoplanets. So today, right, we have oxygen, carbon dioxide, nitrogen, a little bit of methane in our atmosphere. So if you were to see those things, you might think, oh, that’s pretty great. But you might also be interested in a planet that is maybe an earlier version of Earth that maybe has no oxygen but maybe high levels of CO2, nitrogen, and methane. So there’s a lot of different things maybe that you’re looking for. And all of those tell you something about the potential habitability of that planet.
Host: So because we’re looking for, I guess, different versions, you know, we’re carbon-based life forms and we often hear that used as kind of benchmark for the possibility of life. Is that correct? Or even a consideration in astrobiology, or are there other biochemistries considered like maybe silicon?
Becky McCauley Rench: Yeah. So it’s such an interesting question. I love thinking about the different chemistries that life could have. The chemistries that we see in life on Earth are very likely very related to the environment of the Earth whenever life arose, right? So if there was a lot of carbon, there’s phosphorous, sulfur, you know, these elements at certain levels in the environment, and then as you make the move from abiotic chemistry happening to biological chemistry happening, the types of chemicals that are being used is probably fairly similar. So a lot of the chemistry you see in life on Earth is of our environment. So it’s not that hard to imagine that if you had a world with very different chemistry going on, yet you still had life emerge on that planet, that life would also have a very different chemistry. The one thing I’ll put in as kind of a caveat is that look at the chemistry of life on Earth, and you look at water, like water as the solvent and carbon as the kind of backbone structure. These elements and the chemistries of them are really great at doing what they do. And even whenever you look at similar elements along the periodic table, they don’t necessarily have all of the same awesome properties that we see, not the, I guess like physical interactions that you see with water as a solvent, where you see like hydrogen bonding and you see like, you know, you can fill a glass a little bit over the top. Things like that are very important to the way that enzymes and things work in life and biology on Earth that you wouldn’t necessarily get with a different solvent. And the same is true of carbon, right? The way that carbon bonds and the strength of those bonds and the different types of bonds are really fantastic and open up a lot of doors in terms of biological chemistry. So it’s not to say that you wouldn’t be able to have life that didn’t use those chemistries but looking at the example we do of life, there’s a lot of really unique things we see that make us think that that’s, you know, maybe more likely than other kinds of chemistries.
Host: Wow. There’s a lot to consider there. Now, I was talking recently with astronaut Zena Cardman, and she told me that most life on Earth actually lives in the dark, either below the surface of the planet or as the microbiome inside other creatures is light one of the factors that you consider when you’re looking for life in outer space?
Becky McCauley Rench: So what we’re looking for is energy sources. So one thing we know about life is that it needs energy in order to maintain its structure in some way, it needs something to maintain a separation between itself and the environment that it’s interacting in. And that takes energy. So on Earth, we see that in terms of photosynthesis, right? So that’s energy comes in from the Sun. But then we also see it in terms of using organic molecules. That’s what you and I do. We eat sugars, carbohydrates, we use those to make energy. And then there’s all sorts of other chemical reactions that life can take advantage of, iron metabolism, sulfur metabolisms, all sorts of things. And there’s no reason why light has to be the primary energy source. The one thing I will note is that it’s a really good energy source. And then the byproducts of it are also a really good energy source, right? So plants use the sunlight and then we eat the plants and we get energy that way. But absolutely correct. Most life on Earth is surviving in environments and has nothing to do with light. Light is definitely not a necessity for life to be on a planet. Let me tell you something interesting though about light, which is that the spectrum of photons that life could probably use to get energy is actually quite broad. And we have researchers that we fund in the astrobiology program that have actually looked at phototrophs, right? So organisms that are eating light to make energy, and we have astrobiology researchers that we fund at NASA that have looked at phototrophy in caves. So obviously think caves, they’re dark, but there is invisible light, so infrared light that makes it kind of further back in these cave environments. And you can even find likely phototrophy happening even in those like far back places. So even if it looks dark to you and me, there still may be energy there for light for life to utilize.
Host: That’s incredible. So we were talking a little bit about photosynthesis there. So the plants on Earth are green because of the chlorophyll that provides them with the photosynthesis and chlorophyll is green because that’s due to the color of light coming from our yellow sun. And that’s the most efficient wavelength for them to process for energy. When you’re looking at life on other plants, would you expect their plant analogous life forms to maybe be a different color because of that?
Becky McCauley Rench: So it’s definitely possible. Interesting that you mentioned green algae and things like that. There’s actually a lot of different colors, photosynthesizers, even here on Earth. So if you look at maybe different algae at different levels in a water column because of the light that filters through the water, you will get different colors or different photo pigments that they use, which is why you end up with not just green algae, but you have red algae, have brown, so we find these purple photosynthesizers in lake environments, so you can get different color pigments even here on Earth, right? Because they’re looking for whatever energy source is easiest to use in their niche space. And the same is true for another planet. So if the spectrum of light from a star is different, then the life that evolves on that planet is going to find a way to most easily and effectively and efficiently utilize that light through some sort of photo system or some sort of enzyme to create energy for it to maintain all of its biological processes. And so, yes, they could definitely be different colors, just like we see here on Earth.
Host: Fascinating. I did not realize that there were so many different colors of algae.
Becky McCauley Rench: There are.
[Laughs]
Host: Here at JSC, we have the curation facilities for the astromaterials. And how do these astromaterials help us understand life in the universe?
Becky McCauley Rench: Yeah, so the astromaterials at Johnson are great. Lots of meteorites, various kinds of meteorites. What these tell us is very important as it relates to the early solar system and our understanding of organics and abiotic processes that both deliver organics to planets where may be life forms, but also just our general understanding of how organic chemistry works out of a system that is so dominated by biological chemistry like the Earth, right? So looking at the organics in meteorites and understanding how they’ve been altered or how they’ve changed and what kinds of chirality, so like the shape of those molecules is different, really helps us understand how it is that we’re going to look for signatures of life elsewhere and how to differentiate between just organic chemistry that’s happening in an abiotic place versus something that is potentially a signature for life.
Host: Amazing. So I recently heard in the news that the Mars rover Perseverance has had a big discovery that excited a lot of astrobiologists. Can you tell us about what that is?
Becky McCauley Rench: Yeah. So this is the Cheyava Falls rock, which is very intriguing. It had three components to it that made it very intriguing to astrobiologists. One was the white veins of calcium sulfate that suggests water probably flowed through that rock. The second was some reddish area where SHERLOC, one of the instruments on Perseverance detected some organic compounds, so water organic compounds, and then it has these leopard spots that are really cool that suggest that maybe there were some chemical reactions that occurred there. The one thing I’ll say is that it’s intriguing, but we need to wait for the peer review process and the scientific paper to come out so that way we can learn more and we can get the entire scientific community analyzing and assessing the data so that we can come up with all the potential hypotheses because one of the things we want to make sure we do in astrobiology is utilize understanding of life at Earth and try to make the data kind of stack up to get to any sort of answer around a biosignature.
So what we do, something that’s called, we call the latter of life detection where we, you know, you start at the bottom and you have evidence and then you kind of keep working your way up. And as you go further and further up, you get closer and closer to being able to say that you’ve detected life and every little wrong along the way is useful in our understanding of the distribution of life in the universe, whether something’s a biosignature or not.
Host: I think I’ve seen that that latter drawn out and it kind of helps you weed out abnormalities and stuff that like contamination or could this have been done by any sort of inorganic process or abiotic process? Is that correct?
Becky McCauley Rench: Yes, that’s exactly right. So this is exactly the same thing I was talking about with the astromaterials there at Johnson and how they help us understand the abiotic that we’re going to see in organic compounds and compare that to something that we can be more certain is of biological origin. And so, you know, it’s, it’s hard to draw that line really distinctly, but the more and more evidence you can do and stack up and the context around that evidence can get you closer and closer to being able to definitively say, we have found life somewhere else. And that’s where we want to get to.
Host: Amazing. So is it one of the goals of astrobiology to kind of reconstruct a picture of ancient Mars’ landscape in a way similar to what like paleontology and related fields do on Earth?
Becky McCauley Rench: Yeah, so Mars is definitely one of the targets in our solar system that’s most interesting to astrobiology. I would say over the years, what we’ve done is we’ve put Mars climate history to the point where we now know that it was once a habitable planet. And with that knowledge, now that we know it was once a habitable planet, so like 3.5, 3.8 billion years ago, right? Earth and Mars are like sitting here in the solar system and they look similar. And Earth had life out right around in that timeframe. So the question becomes, did Mars have the same thing? And regardless of the answer to that question, it’s actually quite interesting, right? Because it is what happened on Earth. So if it isn’t what happened on Mars, what was the difference? What was the reason it happened on one planet and not the other? And so really from an astrobiology perspective, that’s what we’re interested in doing at Mars. We’re interested in reconstructing that history and then understanding how it either went from an abiotic world to a biotic one, or how it never managed to go from an abiotic world to a biotic one. And we’re really interested in that story either way because it will tell us something about the way that life originated here on Earth. The one thing I’ll add to that is that not all Mars scientists are astrobiologists. And so there’s a lot of people that are also interested in Mars just as a planet in its own right. And the fact that it can tell us a lot of things about how a planet works independently of astrobiology, right? You look at Earth and you look at everything we understand about our interior and our core and all sorts of stuff. And, you know, going to Mars and looking at the same sort of thing teaches you a lot about Earth as well.
Host: Fascinating. And the parallels of, you know, early ancient Earth and early ancient Mars are something that I had not considered. And it that’ll be really interesting as we find out more about Mars to find more of those parallels. And definitely this Perseverance discovery is something that we will definitely be keeping an eye on.
Becky McCauley Rench: Yeah, I’m very excited to see those samples return eventually and to actually be able to bring them into the laboratory and do the really fine scale measurements that we need to give us some great context to what’s there.
Host: That’ll be really amazing when it happens. And I’m sure that those will have some really cool discoveries. And I know we’ve got a lot of these upcoming missions that will be forming a lot of science that are useful to astrobiology. Can you tell us a little bit more about Europa Clipper and the Nancy Grace Roman Telescope?
Becky McCauley Rench: Yes, absolutely. So let me start with the Nancy Grace Roman Telescope. So it’s a microlensing survey of the Milky Way, and hopefully we’ll find, you know, thousands of exoplanets. So that’s amazing. And I also highly encourage people to read about its namesake, Nancy Grace Roman, and her career. She’s kind of an amazing person whenever you think about a woman deciding to be an astronomer back in late 1930s and kind of being one of the first people to be in charge of space-based observatories at NASA. Anyway, she’s an amazing figure, so that’s very cool. And that will use chronograph, like we talked about earlier, and will help us help it kind of block out the starlight from stars so that it can do a better job of observing exoplanets.
Europa Clipper, I’m very excited about. I’m actually planning to head to the launch of that. It’s scheduled to launch on Oct. 10. And taking my kids, very hopeful they’ll get to see this take off cause watching something launch in the outer space is a very just amazing experience. I hope everyone gets to experience that. Europa Clipper is going to be in the Jupiter system for a while, and it’s going to do these flybys of Europa, and it’s going to actually get pretty close. You know, just tens of, the closest flyby, I think is like tens of kilometers off the surface. And what it’s going to do is it’s going to give us some great insight into what Europa actually is, right? So right now, we speculate that Europa has this ice, this thick ice shell, and that underneath of it, there’s this liquid ocean. Well, Europa Clipper is going to tell us whether or not that’s true or not. So it’s going to tell us about whether or not the surface is active. It has some great instruments on board to tell us maybe how deep or thick that ice cap is, how, if there’s any warm spots, may be able to give us some information about organics and the presence of organics. It’s one of the things we’re looking for in terms of habitability, what sort of temperature pressure, salinity that ocean may have. And so while Europa Clipper’s not going to directly search for life, it is a very important astrobiology mission in terms of the fact that it’s going to give us insight into whether Europa has the potential to be a habitable world. And we’re very interested in that.
Host: As a fan of the “2001: A Space Odyssey” series, I am always very interested in anything coming out about Europa and its potential habitability, that is incredible, and that will definitely be a mission to watch.
Becky McCauley Rench: I agree. It’s going to be amazing. And, you know, I’ve been so amazed at the mission team, you know, I’m not directly involved in it, but the engineering feats that they have accomplished, especially these last few months, is just a real testament to the effort and the blood and sweat and tears that the team has put into making this mission a reality.
Host: Okay. So that brings us to the Habitable Worlds Observatory, which we mentioned earlier. Can you tell us some more about that?
Becky McCauley Rench: This is a really cool mission. It’s in the very beginning of its concept. Its main mission objective is to identify and directly image, right? So we talked about indirect and direct imaging. So this would directly image at least like 25 potentially habitable worlds around other stars. And then it would also use spectroscopy to give us some sort of idea of any potential biosignatures in those planetary atmospheres. So that’s pretty amazing to think about happening in the late 2030s. Right now, there’s lots of mission, or not mission teams, but science working groups that are talking about what sort of instruments they want to use, what sort of data they want to collect, what sort of targets they would look at. And so it’s very much in the let’s figure out what this is going to look like, phase of mission development
Host: That sounds really cool. And to get more direct imaging of exoplanets and other potential worlds is going to be really cool to see what comes out of that.
Becky McCauley Rench: Yeah, this is actually one of my favorite topics because while I’m not an astrophysicist, right? So I wouldn’t necessarily do anything with the Habitable Worlds Observatory. I see it as one of the first missions in a long path of missions to eventually get us to a probe around a habitable planet and another solar system where we could actually get data back. And the first thing you have to do if you ever want to do a mission like that, which is, you know, feels like science fiction has a lot of things we have to figure out between now and ever making it happen. But the first thing you have to do is identify the targets, and that’s what Habitable Worlds Observatory will do.
Host: Incredible. And that just makes my science fiction-y heart very happy to hear that we are taking those first steps towards something like that.
Becky McCauley Rench: Yes, I am very excited about it as well. You know, I really hope a hundred years from now, the planetary scientists are getting data back from a planet that is not in our own solar system.
Host: Oh, that’s an incredible thought right there. So, to wrap things up today, can you tell us how does this research help people on our planet right now? Why is it important to look at these worlds if they’re too far away to visit anytime soon?
Becky McCauley Rench: Yeah. So back to that question of alone that I think is just part of the human psyche that’s so important for us to answer. We don’t know about or else, or what made it so that life was here on Earth. And I think we really want to know the answers to those questions. And so I think that this is one of the most fundamental questions, that humanity wants to see answered by the sciences. And we’re taking very tangible, discreet steps to actually get to the answer, right? Like, this is not as science fiction-y as it might seem sometimes, it’s not science fiction, it is science. And we are getting closer and closer to the answer of whether or not we are alone. Just like I was inspired, I hope that everything we do inspires, you know, the rest of humanity to be interested in the science and the engineering and all of that. And then, you know, to see all of those benefits come back to home, you know, everything we do in space exploration starts right here at Earth. Everyone that’s building our space missions and spacecraft and doing the data analysis, they all live here on Earth. And so I think that, you know, that in of itself is a huge boon to humanity.
Host: That is a fantastic reason to keep doing this research, and I look forward to finding out more as each of these missions moves forward and finds out more about these other planets. Becky McCaulay Rench, thank you so much for coming on Houston We Have a Podcast today. This was absolutely fascinating.
Becky McCauley Rench: Thank you so much for having me. I’ve had a really good time. It’s a great conversation.
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Host: Thanks for sticking around and I hope you learned something new today. To find out more about this fascinating and wide-reaching field, check out astrobiology.nasa.gov. There’s so much information there, including a series of graphic novels that detail the history of the field. Our full collection of episodes is on nasa.gov/podcasts, and you can find the many other wonderful podcasts we have across the agency there as well. And speaking of those wonderful podcasts, do yourself a favor and check out Curious Universe and Universo Curioso. They both released deep dives on the Europa Clipper mission earlier this month.
On social media, we’re on the NASA Johnson Space Center, pages of Facebook, X, and Instagram. Use #AskNASA on your favorite platform to submit your idea or ask a question, just make sure to mention is for Houston We Have a Podcast. My conversation with Becky McCaulay Rench was recorded on Sept. 18, 2024. Thanks to Will Flato, Abby Graf, Jaden Jennings, Tahira Allen, Daniella Scalise, and Gary Jordan. And of course, thanks to Becky McCaulay Rench for taking the time to come on the show. Give us a rating and feedback on whatever platform you’re listening to us on and tell us what you think of our podcast. We’ll be back next week.
This is an Official NASA Podcast.