EPISODE 86: ASTROBIOLOGY RESEARCH COORDINATION NETWORKS

Transcript

Mary Voytek: My understanding is we’re now up to at least 5,000 confirmed exoplanets. So, all of a sudden, we have even greater possibilities for life to exist somewhere because we’ve got all of these planets around all the stars in our sky. And we already know that a significant proportion of them are likely to be habitable.

The Research Coordination Networks are virtual structures. It allows people to collaborate across divisions and disciplines and geographic locations in order to advance the research and move us closer to our goal of finding life elsewhere.

Deana Nunley (Host): Welcome to Small Steps, Giant Leaps, a NASA APPEL Knowledge Services podcast where we tap into project experiences to share best practices, lessons learned and novel ideas. I’m Deana Nunley.

NASA has a long history of supporting research in the search for life, dating back to 1959 when the agency’s first exobiology grant was awarded for the development of the ‘Wolf Trap,’ an instrument to detect microbial life on the surface of another planet.

As the field expanded over the following decades, the concept of astrobiology was developed, and NASA became the main supporter of astrobiology research. In 2015, the NASA Astrobiology Program announced a new programmatic infrastructure known as Research Coordination Networks. And that’s the focus of today’s episode.

Our conversation is with Mary Voytek, the Senior Scientist for the Astrobiology Program in the Planetary Science Division. Mary, thank you so much for joining us on the podcast.

Voytek: So happy that you asked me to join you. This is great.

Host: Let’s start with the basics about the NASA Astrobiology Program and the Research Coordination Networks. Could you explain the program and the networks, and what they are and how they work?

Voytek: My pleasure. So, the Astrobiology Program at NASA is about the understanding of how life emerged and evolved on Earth, understanding the limits to life on Earth and how we can use that to ultimately look for life beyond Earth, both within our solar system and even further on, as we’ve discovered exoplanets that could also support life. The actual research that’s entailed in understanding those three very important questions involves many different disciplines. Some people make fun of astrobiology and say that it’s a discipline without a subject because they think astrobiology means the study of life in a star. But I like to think of astrobiology as pointing out the importance of all the disciplines and all the events in the origin and evolution of our solar system even that led to life. So you begin with a star, you form planets, those planet surfaces become habitable, are conducive for prebiotic reactions and eventually you end up with life.

It’s very well captured in a quote I like to use from Carl Sagan that, ‘In order to bake an apple pie from scratch, you must first invent the universe.’ And that’s really what astrobiology is all about. So as we have all these disciplines, how do we get researchers to talk to one another? To not just pass the baton as I study a star and then somebody else has to pick up from the star, move to the next research project or the next logical level in the progression of understanding how life began. But in fact, we need them to work together.

And so, coordinating the research that we fund in the NASA Astrobiology Program, whether it’s amongst the individuals that we fund or a broader community, requires significant effort. And the Research Coordination Networks are just such an effort that we have put into place. What they are, are virtual structures. We have five of them actually in the program. It’s a virtual structure that brings together researchers around a central question in astrobiology, and it allows them — since it’s virtual and since everyone’s invited to participate in this — it allows people to work and converse and discuss and collaborate across divisions and disciplines and geographic locations in order to advance the research and move us closer to our goal of finding life elsewhere.

Host: Could you tell us about the new RCN that was officially launched last month?

Voytek: We’re very proud of this. This is our fifth and for the moment the last one we had planned. And it is called LIFE, and LIFE covers the emergence of life. So primitive cells, as we can recognize them as life, and then looks at the evolution of life all the way to multicellularity, which is those events and that process of evolution really changed life into something that possibly was happening in a very limited area into becoming a planetary process where we start seeing life interacting with its environment in such a way that it’s shaping the chemical reactions. The way the climate operates or patterns of circulation in our oceans are now becoming affected by what’s going on in terms of life. And so it becomes an integral part of the planet at that point. And that’s what this RCN is focused on.

So, they’re picking up the baton from one of our other RCNs that’s called PCE3, or Prebiotic Chemistry and Early Earth Environments, that deals with those abiotic processes that are morphed into something more prebiotic or probiotic. As you see, we’re getting closer to something that’s relevant to life. And once you have all that in place, that jump to that first cell, that first organized entity in the environment, that’s what this group is looking at.

Host: What excites you most about the LIFE RCN?

Voytek: Well, I think it’s that bridge, that transition to life from non-life. Right now, all the research that we’ve done in our understanding makes it almost like a switch. We understand what was happening before there was life, and we understand what was happening after we have life. And the RCN LIFE is going to really address how we manage to go from one to the other. And I think that is one of the most important questions in being able to tell if it’s likely that life emerged somewhere else, not only on our planet, but at other places in the solar system.

Host: And what’s the definition of life?

Voytek: That’s a great question. And I get asked that a lot, and my answer is very unsatisfying. We always say, ‘You ask a hundred people that are in astrobiology even to give you a definition of life and you’ll get about 110 of them.’ We can’t really agree on it, and some would argue we don’t really have a definition of life the same way we have a definition of some physical principles like understanding the Higgs boson particle or whatever. We just don’t understand life at that level. But what we do understand are certain features that life expresses or phenomenon that’s associated with life that we can use to actually look for life, even if we don’t know exactly the best way to define it. So we know things like it requires energy. It uses carbon as well as several other elements like carbon, hydrogen, oxygen, phosphorus, sulfur, I must be missing something in there. Maybe nitrogen, I forgot.

But it’s a series we call it CHNOPS. It’s a series of elements that make up all life as we know it. And so life as we know, it’s carbon based and that’s the dominant element in it. And we also know about the other elements that it needs. And we know that it must be able to reproduce, and it must be able to adapt and evolve. Because anything that can’t adapt or evolve is likely to be left behind as our planet and its localized environment changes. So, it’s energy, it’s nutrients. It’s the ability to reproduce, and the ability to adapt and evolve are the really key things that are important to our understanding of life.

So, whether or not we have an absolutely, perfect, universally accepted definition or not, astrobiologists think that we know enough about the features of life and how life functions on Earth that we could use those features as targets for missions and our investigations as we search for life beyond Earth. So, we can look for, for example, energy sources — we can look for some reproduction. We can look for chemicals that are made by life as we know it, but that are complex and would only be made if life were there. And so, I think that we think we’re in a fairly good position. That does not mean, however, that we don’t still strive to come up with that universal, unifying definition.

Host: The LIFE RCN joins four others, as you mentioned, that were already in existence, including PCE3 that you briefly touched on. What are the other networks and what’s the focus of each RCN?

Voytek: So, we have four other RCNs and each of them address one of the three goals of the Astrobiology Program, which is either looking at the origins of life, which we already mentioned the RCN LIFE does a little of that, but also PCE3, Prebiotic Chemistry and Early Earth Environments. So, it’s looking at the emergence of reactions that produce compounds and chemistries and modify the environment that makes it right for the eventual emergence of life.

And then we have the three remaining ones really focus on our search beyond Earth. The first one I’ll mention is called NfoLD. It’s the Network for Life Detection. And as it says, it brings together people that are interested in the science of life detection. And that includes people who are researching exactly what features of life we should be looking for. And a lot of what they research are based on what we understand life specifically does here on Earth.

So, there’s some people that think that looking for molecules, like DNA, that are involved in heredity and reproduction would be important to look for. Some are looking at things that are more agnostic to the life that we know here on Earth. And so that’s trying to abstract a fundamental concept in life without looking specifically at the solution that life on Earth has come up with. So, for instance, maybe not look for DNA, but we know that there has to be a molecule that stores information, so what else could do that? The worst thing in the world I could imagine, and this RCN would tell you, is if we went somewhere, we had instruments to look for life as we know it, and there is life there sitting right in front of us, but we don’t recognize it.

So, there’s a whole branch of people working on something we call agnostic biosignatures and those are really important to maximize our search efforts. And then along with the scientists that are studying those features of life that we could look at and looking not only at what the features are, but how well they’d be preserved and what else we might need to measure when we’re looking at them. We’ve also included in that RCN, the engineers and technologists that are developing instruments and are involved in missions that would eventually be developed to go search for life somewhere. So rather than get those people together, sort of right before it’s time to launch, this RCN gets the scientists and the engineers together at the very beginning in a really nice iterative process.

The next two are focused on targets. One of them is called NOW, the Network for Ocean Worlds. And it focuses on not only oceans on our own planet and specifically looking at the deep sea here on Earth, but also what ocean worlds might exist beyond. And two that people are familiar with and have heard a lot about in the last few years are in Enceladus and Europa, which are two moons. They orbit Saturn and Jupiter, respectively, and NASA is very interested in going there to look specifically for life. We’ve already gotten some indicators that the subsurface ocean of these icy satellites could be habitable, which is really important. That means that there could be nutrients there. There could be energy there that’s available. We just have to come up with clever ways to actually go there. And this group is working on the oceans, the icy lids on them, the icy surfaces to understand how those moons operate and could generate what’s needed to support life.

In the past, I would say that the strategy for looking for life beyond Earth has been to follow the water. And we’ve gotten far more sophisticated in looking for other things that are important for life. But if you do stick with the follow the water, what better place to go to look for it than an ocean that’s out there orbiting our gas giants. So that’s what NOW is about. And again, they have geophysicists that study the ice. They have oceanographers and microbiologists and chemists and you name it. They get together. They’re all brought together because we are looking at these bodies as systems, and it takes the entire system to really support life.

And then the final one was actually the very first one that we put together and it’s called NExSS. It’s the Nexus for Exoplanet System Science, and not surprisingly, it’s extraordinarily interdisciplinary. It ranges from everything from astronomers to biologists — another way to think about astrobiology. We’re looking at planets orbiting the stars in our night sky.

I saw a talk by Natalie Batalha, who when she was still working with us at Ames, she was the project scientist on Kepler. And she said after working on Kepler and their discovery of multiple planets — and I think my understanding is we’re now up to at least 5,000 confirmed exoplanets — that at night, when she looks up in the sky, she doesn’t see stars. She sees billions and billions of solar systems. So all of a sudden, we have even greater possibilities for life to exist somewhere because we’ve got all of these planets around all the stars in our sky. And we already know that a significant proportion of them are likely to be habitable and we define that as a planet that has water on the surface. And so those tend to be ones that are positioned at a particular location relative to its star so that it can support life.

And so, this particular RCN works with all these groups to understand the habitability of exoplanets. What can we learn? Because the challenge with exoplanets is we’re looking using telescopes. We won’t go there any time in my lifetime, for sure, to actually be able to observe them directly. So all of our observations and all the data that we collect are going to be from either ground-based or space-based telescopes. And so they’re working together to figure out what features that can be measured from afar can tell you something about the makeup of the planet, whether or not it’s got an atmosphere. Is there water on the surface? Is there any sign that there’s a pigment? And then to start looking for even more specific signs, not of habitability, but of life itself. Is there oxygen in the atmosphere that you don’t expect to see unless there was photosynthesis going on the surface? And so, their focus is really about understanding exoplanets as a system and how do you tease out from what you can measure? What exactly is going on? And is there a possibility of life on its surface?

Host: That was a fantastic summary of the RCNs. How do the RCNs tie in with NASA missions?

Voytek: Each and every one of them has something to contribute to the missions that we have ongoing, or we have planned and beginning to be developed and even some ideas we have for the near future. NExSS is important because of TESS that’s already in operation, JWST coming online and the future concept missions that were evaluated in the Decadal Survey, HabEx and LUVOIR, which are these space-based telescopes that will help us do that. NOW is important because of what is coming up, we had Cassini, but now we’re going to go back with the Europa Clipper and learn more about Europa. Those are specifically related to missions and the connections are really obvious, but not to miss out on the connection between the Prebiotic Chemistry and Early Earth Environments.

We have a mission called OSIRIS-REx that went to our carbonaceous asteroid and is bringing back materials and this is about the earliest materials in our solar system. The connection to PCE3 is that we’ll understand about reactions that can happen on a body where life didn’t evolve. So, we don’t think that there is any life on Bennu, but we know that there’s carbon there. And it’ll be very interesting to get an inventory of the types of chemicals and organics that we see there. And that’ll tell us something about what was available at the very beginning.

And then the other really interesting mission in planning is Dragonfly. This is a mission to send a quadcopter to one of the other moons, icy moons called Titan. And Titan is the only other body in the solar system that has a liquid on the surface, but its liquid is made up of ethane and methane and we know that it has very complex chemistry in its atmosphere. And so, this mission is going to try to understand the organic chemistry going on that moon and look to see specifically, one of its goals is to see if any of those reactions look anything like the reactions we think occurred on Earth early on. So again, the connection to PCE3 is very strong there.

And our most recent RCN LIFE is dealing with major innovations that life had, that I mentioned before. Turn life from being just sort of almost an afterthought on a planet to be an actual planetary process. And the most obvious one that everyone is aware of is when photosynthetic organisms converted the atmosphere of Earth from one without oxygen to one that is oxygenated and it’s the atmosphere that we enjoy today. And so, LIFE is going to inform us about what other things you could look for in addition to oxygen as these metabolisms and early life and as it evolved, what metabolisms might be possible to look for, specifically on exoplanets. One of the things that they’re going to be looking for is the presence of oxygen in an otherwise reducing situation in the atmosphere of an exoplanet. Does that say that there’s photosynthesis going on there? And so, all of them are connected also to missions.

Host: Based on your interaction with the science community, how would you rate the success of the RCNs?

Voytek: Well, I, of course, think it’s extremely successful and the people that are in an RCN seem very excited about it and they acknowledge they are a lot of work. Collaboration is tough. It requires energy and effort. But they have already started to see the benefits of being able to talk to your colleagues about research that you’re interested in. And so the makeup of the RCNs , the core group, let’s say, they’re called the steering committee, are made up of funded PIs at NASA. And then they have a broader membership that includes these affiliates and what they are doing for themselves in the community are organizing a variety of events that allow really good productive discussion to move the science ahead. So every single one of the RCNs that have been in existence have hosted at least one, in many cases four or five workshops, to get at the heart of important science issues covered in their theme.

And people that participate in them get out of that a better understanding of the scientific problem. They get ideas for solutions, for new research opportunities and ideas for proposals. I think that there are a number of people that don’t understand it well enough. Because even though the first one was established in 2015 and it was for exoplanets, that one has been extraordinarily successful, and people see that. But they’re still a little hesitant to declare victory on the ones that we most recently established. But I’m just thrilled when I go to these workshops, people are so engaged. I have seen it change in the sort of proposals that I get, an enthusiasm for the research, because it’s a team working on a problem. To me, it’s quintessentially NASA. I’m reminded of Apollo 13 and people working together to figure out what to do to make something work and to fix some problems. I just feel like these RCNs do that too. And the only difference is they’re not all in one room or stuck in a spacecraft. They’re geographically distributed.

Host: Mary, what are some ways NASA’s Astrobiology Program, and specifically the RCNs, are connected with Mars exploration?

Voytek: So, Mars is very important for a number of reasons in astrobiology. I mentioned that we start with the star and the formation of the planets. Well, the three closest planets, Venus, Earth and Mars, are a perfect triplet to study to understand how a planet becomes able to support life and how it sustains that ability to support life, or it sustains its habitability. So, we understand that both Venus, or we believe, that both Venus and Mars were much more habitable, in fact, a lot more like Earth in their past. And so, it’s important to study Mars just to understand what was, what could be, and as a comparison to Earth. It’s also important to look at the possibility of life there. It’s been the center of our efforts in terms of astrobiology missions.

As early as 1976 we sent two landers, the Viking Landers to Mars, to look for, well actually to do a life experiment based on what we understood about life. We did a number of experiments looking for organics and the utilization of organics and remarkably, at the same time that mission was getting somewhat ambiguous results, unfortunately for them, but very fortunate for astrobiology because it really highlighted how little we knew about the environment and how limited our understanding of life was. At the same time that data was being collected, a submersible had stumbled upon the hydrothermal vents, and you Deana may know about the hydrothermal vents. They’re a system in the deep sea that supports an oasis of life. There are these giant worms at some of them and huge clams. I mean, they’re just overrun with life, and they’re located along active tectonic sites. And because of the interaction between the rock and the fluids in there, it creates chemistry that can support life. And until we found them in ‘76, ‘77, we thought that the only life on Earth had to originate from the energy from the Sun. So, the Sun creates the plants and animals eat the plants, and then we eat the animals and the plants. But everything, even though it was chemistry and chemical energy that we were getting, it all started with the Sun. And here were these systems as alien as anything we could have found on Mars, that were creating life hundreds and thousands of meters away from the surface of the planet where sunlight would reach, here was this oasis of life. And so those two discoveries really set off astrobiology and how we understand what we don’t understand about life and what we need to do to be better at preparing ourselves for the search.

And so specifically, the RCN that is most relevant to Mars exploration is the NfoLD, the one that’s looking for specific biosignatures to hunt for looking at how they can be preserve so that when we go to Mars, we know where to look. The most recent mission to Jezero Crater — that location was selected because of our understanding how life may have emerged or how conditions favorable for life can be created from impacts and hydrothermal activity. So, Jezero Crater was selected. And one of the amazing things about that mission is they’re collecting samples they’re going to bring back and astrobiologists as well as planetary scientists are going to be examining these samples, looking for evidence of ancient life.

Host: Well, Mary, this has been so fascinating. Thank you so much for joining us on the podcast.

Voytek: Thank you so much. I really appreciated the opportunity to talk to you and to get out the message about how great astrobiology is to my colleagues and the public.

Host: Do you have any closing thoughts?

Voytek: Well, what I like to say every time I meet anybody is we’re all astrobiologists. You just don’t know it yet. I think we all seek to have answers to the questions that astrobiology asks, and we all have something to contribute to the effort to understand our origins, our evolution and if we’re alone in the universe.

Host: Mary’s bio, links to topics discussed during our conversation, and a show transcript are available at APPEL.NASA.gov/podcast.

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