"Nobody is looking for a green man anymore." Although life in space may not exactly be E.T. over again, it seems unlikely that we are alone in the universe.

About the Episode

In this very first episode of Big Ideas Only, we’ll explore the topic of life in space: What it is, where we are looking, and how we hope to find it.

Today, our guest is Kai Finster, professor of Astrobiology at Aarhus University. He’ll touch on everything from why we are looking for exoplanets to what the habitable zone is and why life in space will (most likely) be unicellular.

Your host is Mikkel Svold, CEO of Montanus, who will guide you through this interesting topic of Life in Space.

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In This Episode

Listed below are the most essential timestamps from the podcast episode to make it easier for you to find the topics that interest you.

01:01             What is astrobiology?

02:13             Are we alone in the Universe?

03:16             The definition of exoplanets

03:47             What is the habitable zone?

06:27             Life on Earth

07:28             Why does the possibility of life in space interest us?

09:44             How do we know water is a key ingredient of life?

13:13             Unicellular vs. multicellular life

19:06             What are we looking for on Mars?

26:19             Analogs

32:03             Where will the research take us now?

38:54             Future missions on Mars

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Full Episode Transcript

Mikkel:

Hello, and welcome to this very first episode of Big Ideas Only, a podcast brought to you by Montanus, a company where we specialize in producing high quality content for marketing departments in high tech companies. I’m Mikkel Svold, and to kick off this very first episode, we’ve decided to go with what might be, I guess, the biggest idea around. So in this episode, we’ll ask the question that has baffled humans since the dawn of time, namely, are we alone in the universe? And to answer this question, we’ve invited Kai Finster into the studio. Welcome Kai.

Kai:

Hello, welcome.

Mikkel:

Kai is a professor of astrobiology at Aarhus University in Denmark, and astrobiology is basically the science of livable or habitable places outside of planet Earth. It may be, or what is the actual definition, Kai?

Kai:

Yeah, I would say the definition is a bit broader, and includes Earth actually. I mean, the definition that you just mentioned is the definition that was given 50, 60 years ago, when the field started by Joshua Lederberg, who was one of the first to launch this term, and they called it at the time, “Exobiology,” which means life outside of Earth. The problem was, that has always been the problem with the subject or the field is that we have not yet discovered life outside Earth. So studying life outside Earth would be a quite sad and boring topic to study.

Mikkel:

Yeah.

Kai:

So, we study the habitability, that’s correct, but it’s mainly with respect to what we know about habitability and life on Earth. So our reference for everything that we do is terrestrial life, and Earth is our model system, so to say.

Mikkel:

Okay, and let’s just jump right into, I guess, the big question of them all; are we alone in the universe?

Kai:

Yeah, that’s a big question, for sure. And of course I cannot answer the question, because nobody can answer the question. You can just come up with some ideas about how likely is it, I mean, what has changed our perception and of course, the discovery of exoplanets about 25 years ago. Before that, it was speculated about exoplanets, you can go all the way back to Giordano Bruno, who speculated about worlds in the universe, with all kinds of living things on them. Of course, he had no clue and no background to say anything reasonable about it, but he speculated about it already then. And people have been doing that, but the real breakthrough came about 25, 30 years ago when the first exoplanet was discovered. And since several thousand exoplanets have been discovered around different types of stars, also sunlike stars, smaller stars and dwarfs, all kinds of stars, and the variety of solar systems is extremely broad and fascinating.

Mikkel:

Yeah. And exoplanets, just to define that, right, is not Earth-like planets around in the universe, it’s just planets.

Kai:

Any planets.

Mikkel:

Any planet.

Kai:

Outside of our solar system is an exoplanet.

Mikkel:

Yeah. And I’m thinking about, what about, you say that we’ve discovered, I think’s about 4,000, something like that, planets.

Kai:

The number’s just rising and everything.

Mikkel:

Yeah. And how many of those could be potentially habitable?

Kai:

I can’t give you a number, but I mean the habitable zone is defined as the zone where water can be present in a liquid form around a star. So when we look at our own solar system, the habitable zone would not include Venus anymore, but Earth, lucky enough, and Mars, which is the outer edge of the habitable zone. Venus is in the inner outer edge, so to say of the habitable zone, Earth is just in the middle and has been all the time, and Mars is just about in the habitable zone. I mean, it’s interesting with respect to Venus, because the sun has changed it’s luminosity quite a bit over the last 4.6 billion years, so it was a bit faint, much fainter, 30% fainter to begin with, and that means that there was much less energy. So being closer to the sun was favorable, and Earth in principle had a problem at the time, because it was just about to be outside of the habitable zone, but Venus within the habitable zone. But as the sun has evolved, it has become lighter and hotter, so Venus gradually is moved out of the habitable zone.

Kai:

But this is what we are looking for when we are looking for places outside of our own solar system, and to define them as places, where there’s a possibility or potential for life. And then of course, it’s more than that; it’s also the type of star, it’s a type of planet, everything else.

Mikkel:

And I guess there’s a lot of mathematics going into it as well, or statistical work, where you would calculate on the likelihood of life, rather than is there life or not?

Kai:

Yeah. I mean, but what became clear and this started with the Kepler telescope, which was the real breakthrough in discovering new planets is that it seems to be that there’s no star without a planet. And there’s several stars, and it’s more the rule than the exception that they have several planets, and since we have billions of stars, just in our own galaxy, there are also billions of planets or more. And I mean, it’s still a question of whether you are an optimist or a pessimist. So for the optimist, of course the number is almost infinite of possibilities of life. If you look at the universe, the whole-

Mikkel:

So, they would say, it’s unlikely that there is no life.

Kai:

There is no life. Yeah. But since we haven’t understood how life arose on Earth, it’s difficult to tell. I mean, we just know that life is on earth and that it’s about 4 billion years ago that it started, but we don’t exactly know how it started. So, we know the ingredients, we know what is necessary, and also, we know that all the components can be formed relatively easily, given the right conditions, both in the… Some of it is even formed in the universe or to say it’s not linked to planet in interstellar clouds. Some of it is formed in the atmosphere. Some of it is formed in, we find it on comets, meteorites and so on. So the ingredients, different organic compounds they are present. Question is then to combine them in the right way to make the cells, so to say, and this is not understood.

Mikkel:

I’m thinking, I want to jump to a question that springs to my mind, and it’s a different question because why is it interesting for us to know whether there is life out there? Why is that?

Kai:

I mean, for me, it’s interesting because I’m a biologist. And as a biologist, I am interested in the diversity of life, I’m interested in the evolution of life. And well, we know that all life on Earth has a common heritage, so we all linked at some point in time, we all have DNA, and so we have a lot in common, even though we are quite different when we look at the bacteria-

Mikkel:

So, it’s also to understand life on Earth better.

Kai:

It’s just to understand, it’s to figure out whether this is the way, how to make life. I mean, if you go to Mars, we find life on Mars, and we can identify it as life on Mars, and then we see, okay, it uses exactly this same type of code, it uses DNA, it uses proteins, it has a cell with a lipid cell membrane as a biological cell has. Then we have at least two types of life which found the same solution. And then it seems to me quite obvious that this is probably a good way of how to make life, so to say. If it is completely different, I mean, then it’s even more fascinating and finding life on Mars would be quite fascinating already.

Kai:

But finding, I mean, when we look into the components of life, for example, amino acids. All amino acids that we use in organisms have a, have a certain structure we call them L and this is the type we use. When we look at the sugars, we use a D type of sugar. And it’s so that this is common for all types of life. It would be very interesting to see whether this also would be the case of Martian life, or if they use D amino acids and L sugars, just the opposite [inaudible].

Mikkel:

But, one thing I thought about was how do we know? We look for water, but how do we know that water is the key ingredient? It might just be the key ingredient on Earth. Because you talk about the components of life, but how do you know that are also the universal components of life?

Kai:

Yeah. I mean, first of all, you would need, yeah, I mean just starting with water. I mean, water is the solvent, in that respect, it’s a component, so to say. And water is just universal. So there’s plenty of water all around; it’s made up of very common elements. If you need a solvent, this is a very common solvent. So it’s the most common solvent in the Universe.

Mikkel:

So it’s very likely that it’s-

Kai:

It’s likely that it’s water. And water also has a lot of properties, which are favorable to life. So it has a very high heat capacity, for example. So it would regulate climate in a perfect way. It can absorb, and give off heat and stabilize climate. It has properties that allow to dissolve salts, and stabilize ions, which is also necessary in many biochemical reactions. It supports the formation of membranes, for example, because you have compounds that love water, they’re hydrophilic, and that hate water, so to say, they’re hydrophobic. And if you bring these compounds like lipids, fatty acids, if you bring them in contact with water, they spontaneously form membranes. And membranes are necessary for all cellular life, as we know it from Earth. So, water has a lot of properties that support processes.

Mikkel:

And just to dig into that; the membrane is important to life because it controls what’s on the inside of something and what’s on the outside. Is that the-

Kai:

Yeah.

Mikkel:

That is the function.

Kai:

Yeah. I mean, this is essential. You need to have control over the system. Otherwise, I mean, at the moment, when the living organism loses the control, it dies. It’s dead. So, it’s what we call homeostasis, so that you have an inner and an outer, and the inner is controlled while the outer is quite chaotic. So we need it for energy conservation. The membrane is necessary. Respiration takes place on the membrane with the proton gradient, which is necessary for the formation of ATP. All the type types of synthesis taking place in cells. DNA is polymerized in cells. RNA is transcribed into proteins. So all the different functionalities of a cell require an enclosed and controlled environment.

Mikkel:

Yeah, although they could, so to say, they’ll be flushed out if there were no controlled environment, or they’d just not be able to be there?

Kai:

Yeah. I mean, you can have chemical reactions, but you cannot have controlled chemical reactions. Especially when you look into a cell it’s hundreds of chemical reactions that are taking place simultaneously, and this is only possible when you have complete control over the system. And for that, you need to have an enclosed system, which is provided by the membrane, or the outer shell for the cell.

Mikkel:

And then coming back to this question, whether we are alone or not, what kind of life are we expecting or what kind of life are you expecting? And if you are expecting something, I presume you are?

Kai:

Yeah. I mean, when you look at life on Earth and the history of life on Earth, you could tell that most of the Earth history life was unicellular. For most of the time, bacterial, but then also when it got eukaryotic cell, I mean the cell type, as the type of cells that we have made of with a nucleus, so more complex multicellular life only came in the last billion years, maybe. So 3 billion-

Mikkel:

Of the 4 billion-

Kai:

Of the 4 billion, 3 billion years of life on Earth was unicellular. And I mean, there need to be a lot of coincidence to form multicellular life. One of the major coincidence is to develop the evolution of oxygenic photosynthesis as the photosynthesis that produces oxygen.

Mikkel:

Why is that?

Kai:

Yeah, because without oxygen, you would, you could not have complex life.

Mikkel:

But why?

Kai:

I mean, one of the important aspects is, when you have a food chain, so you have small getting eaten by bigger, getting eaten even bigger, and getting eaten by the biggest ones, in order to transfer energy from one level to the next, you need to have the right type of respiration. If you do that in a world that is respiring without oxygen, other compounds are just fermenting, you’ll have a very, very bad conversion of energy into biomass. So, a lot of it is lost or not available anymore, and this would only allow you for about two steps. So, you would have a very, very short food chain.

Kai:

With oxygen, it’s completely different, because you have a much more efficient conversion of energy from one level to the next, also of matter from one level to the next, and then this allows you to have these long food chains, which gives you the possibility of having more complex life as we have it. So, in a world that has no oxygen it, atmosphere, I would only expect unicellular life. You can have eukaryotic organisms like with the same cell type as ours, but they would not get multicellular.

Mikkel:

Okay. And I’m guessing because of the sheer time span, 3 billion years versus 1 billion years, what you would be looking for, would that be unicellular life rather than multicellular? Because it’ll be more likely to find, wouldn’t it?

Kai:

Yeah. I mean, unicellular life is the most likely to… If there’s any life, this is the one,.I mean, this is the life that we are looking for when we look for life on Mars. So nobody is looking for a green man anymore.

Mikkel:

Oh, unfortunately.

Kai:

Yeah. Well, I don’t know. I would say it’s a waste of time, so you better go for something that is more realistic. So this is what we are looking for, and now the discussion with respect to Mars is when we look back in time, Mars and Earth were not so different to begin with. Of course, Mars was always smaller, so it has less gravity, And so, but to begin with, Mars also was a wet planet; it was not always the dry planet as it is today. And since we think that life somehow evolved, well, water is important, as I said before, it’s not clear whether the ingredients for life came only exclusively with meteorites, or they were formed on the planet. I mean, there’s this famous Miller-Urey experiment where Miller and Urey in the fifties carried out the experiment with an atmosphere that they thought was the atmosphere of the early Earth, and the energy they put into the system, by lightning, just by electrical discharges, so to say, they could see that when they had electrical discharge in a humid atmosphere consisting of methane, ammonia, some hydrogen and CO2, they very rapidly got the formation of different kind of amino acids.

Mikkel:

Oh, really?

Kai:

So, the idea was then that was the start of the primordial soup idea, so that you had this formation of organic compounds in the atmosphere with rain. It rained into the ocean and in the ocean, it was accumulating, and then by some hocus pocus this was converted into a cell in the end. So then, there’s another idea that these organic compounds could form on rocks in wet-dry cycles, so that you have ponds on these rocks that dry out, and while they dry out, organic material is polymerizing combining into bigger, more complex molecules. And then it gets wetted again, and during these wet and dry cycles, you produce more and more complex biomass. And again, by some unknown mechanism, you end up with a cell in the end. So, this could have happened, not maybe not up to cellular life, but in principle, the formation of organic material could have happened on Mars in the same way as it happened on Earth.

Mikkel:

And then, now it would just have been dried out?

Kai:

Now it’s dried out. There’s still some water. I mean, there’s water on the poles and there’s also water-

Mikkel:

Liquid.

Kai:

Oh, it’s not liquid, it’s ice. I mean, the average temperature on Mars is about minus 50 degrees, And it’s changing between 25 plus on the surface, in the daytime to minus 150 nighttime.

Mikkel:

Quite hostile.

Kai:

It’s a very hostile environment. It’s not a place where you would like to be without a proper-

Mikkel:

A proper suit.

Kai:

Yeah.

Mikkel:

Yeah. But so what you’re looking at right now on Mars, what are you searching for right now?

Kai:

I mean, as we’ve just talk about the community, so to say, so there are two missions on Mars right now, rover missions, Perseverance Mission, and the Curiosity Mission. And they are looking mainly for remains of life, so signatures. They don’t have the possibility to look directly for life, in the sense that they are not as sophisticated as Viking in a way, they’re not doing experiments, but they’re doing analysis. So, they drill into a stone, take the stone, put it into an instrument and analyze what’s in there, which kind of compounds and look for different organic compounds

Mikkel:

Yeah. Different traces.

Kai:

Traces of life. And then we have ideas about, okay, which types of compounds could we expect if it was life, that was the origin?

Mikkel:

And what would that be?

Kai:

I mean, it could be some amino acids, for example, could also be some degradation compounds. If you have nucleotide, which builds up DNA, you would expect some degradation compounds of those. So this is the way how we approach it now.

Kai:

And then is a lot, I mean, the other part is to learn a lot about the geological history of Mars. I mean, there has been a lot investigated in the history of water; when did it disappear? Why did it disappear? Where did it go? So this is the other aspect is to understand the magnetic field of Mars; what happened to it? When did it disappear? This had also some very important implications for the stability of the atmosphere of Mars. The other thing is volcanic activity on Mars, because for Earth, we have this idea with like Miller-Urey, that organic material formed in the atmosphere, but there are also some theories about organic material forming around volcanic spots; black smokers, white smokers on the bottom of the oceans. I mean, we have them in the Mid-Atlantic Ridge, for example, areas where very hot, reduced water comes up to the surface and you have these black smokers, small chimneys formed and around-

Mikkel:

So that’s a kind of volcano.

Kai:

A kind of volcano, it’s a very small volcano.

Mikkel:

With smoke coming up.

Kai:

Yeah. And the idea is that this brings different kind of chemicals, and these chemicals can then form the basis for, this is an energy source for more complex organic materials to be formed.

Mikkel:

Okay. So that’s what you’re looking for on Mars as well?

Kai:

Yeah. We are looking, I mean, we want to understand the history of Mars. And then we also looking for hydrothermal systems and hydrothermal systems would be a place to look for and see whether we have fossilized microorganisms, for example.

Mikkel:

Would you expect that there is living microorganisms on Mars now? Or do you only expect to find, yeah, the remains of former life?

Kai:

I mean, it’s quite clear now that at least at the surface it’s most likely to find remains.

Mikkel:

Okay.

Kai:

If you go deeper into the Mars-

Mikkel:

Because of the climate or why?

Kai:

Yeah, primarily because of radiation. I mean, one thing is of course the availability of water; there’s not much water there. And because of the thin atmosphere, you don’t have liquid water. So, water’s either in the form of ice or in the form of vapor. So, but if you could dig deeper, that would be a possibility to find life there. We know from Earth that by far the largest, the most biomass is in the ocean sediments.

Mikkel:

And that means, the place where there is most life?

Kai:

Yeah. That’s where you have the largest amount biomass. And we have been drilling into the ocean sediments and found life in several kilometers depth.

Mikkel:

Oh, really?

Kai:

And if we know from Mars that also on Mars sediments have formed, so it could be possible if you could drill sufficiently deep, you could find areas where life could be possible.

Mikkel:

And the life you find down in these drillings on Earth, how does that work? Because I also think life needs some sun and you need water, obviously, it could be easily water down there, but you would also need oxygen, and how does that work?

Kai:

Yeah, but I mean, this is because we need oxygen and that’s why we think life needs oxygen, but I mean, oxygen is relatively new in Earth history. It starts to accumulate in the atmosphere only 2.5 billion years ago, before that there was very, very little oxygen. So life started out without oxygen, and there are plenty of organisms, microorganisms that live without oxygen. So it’s perfectly possible that organisms could live respiring with other compounds than oxygen. I mean, fermentation.

Mikkel:

Yeah. What could that be? What would they use instead?

Kai:

Yeah. I mean, they could use different minerals. There are organisms that could use rust to respire with. It could be sulfate; the oxidized form of sulfur. So this would be possible. There are methanogens, as I told you already, that methane was found and methanogens uses CO2, carbon dioxide. So there are plenty of possibilities. When we look at life on Earth, there are so many different compounds that microorganisms can use to respire with, alternative to oxygen that we use. And there’s also the possibility that new life can form without light. So we know that there are microorganisms, again, that can use chemical energy, and take in carbon dioxide, and convert carbon dioxide into biomass. It’s a very minor fraction on Earth by far 99.9% of all biomass is formed with photosynthesis. So this is by far the most important process, but there are organisms that live happy life with hydrogen and CO2, like these methanogens from methane and biomass, so that’s all possible.

Mikkel:

Wow. Now, when you look for, I guess, inspiration for what could be life on other planets, could be Mars, but it also be exoplanets outside of the solar system, where do you look on Earth to find inspiration to how it could be? You look in the drillings, down on the bottom on the sea floor, where else?

Kai:

I mean, we work with what we call analogs. That means, analogs are environments that are similar, that have similar properties. So, when you look into Mars, I told you already it’s dry, it’s very cold. So you would look for-

Mikkel:

Like a cold desert somewhere.

Kai:

Yeah. You could look for cold and dry places, and on Earth, we would find some in Antarctica. We have these McMurdo dry valleys where it’s extremely dry and extremely cold, very little biomass. This is an environment that you would go for and see, okay, how can organisms survive under these conditions?

Mikkel:

I visited the Uyuni Desert in Bolivia once, which is like a salt plain, I think might be the world largest salt desert, which is also, well, cold, but it also gets warm. So, it’s a little bit-

Kai:

It’s quite high up.

Mikkel:

Yeah. It’s quite high up and it’s just pure salt. So, it’s just like salt as far as you can see and I’m imagining this could also be a place that presents such a hostile environment, because living on salt.

Kai:

Yeah. But I mean, again, we have to be careful because we consider hostile always thinking about hostile to us.

Mikkel:

To ourselves.

Kai:

I mean, you have organisms that would find it hostile to live in our environment.

Mikkel:

Yeah.

Kai:

I mean, it’s a question of, we have 4 billion years of evolution, so things are getting adapted, and they love to be where they are. So for an organism that lives in these salt pans, it’s just exactly the place where it would like to be. If you put it into Brabrand lake, it will die immediately.

Mikkel:

Yeah.

Kai:

So-

Mikkel:

I guess you’re right. But, so what you do is you look at the planet that you find Mars or some other planet, and you would somehow find out what the atmosphere there is, and then try to find a similar place on Earth or how’s it working?

Kai:

No, I mean, with the atmosphere, this is a different issue; the atmosphere is interesting when we are looking to exoplanets. With Mars-

Mikkel:

Yeah. Because that’s all we can see. Right?

Kai:

Yeah, I mean, we cannot see it, actually. We hope to see it at some point. We can see it with some of the very big planets. The smaller ones, we could just see that there’s a planet and we can get some idea about its size, its density, and also how close it is to the star, and can say something about whether it’s the habitable zone or not. But, when it comes to Mars, for example, then we can look into, okay, where on Earth do we find life? What kind of life do we find there? We al-

Mikkel:

Yeah. Similar places

Kai:

And similar places. And then we can get some idea about the requirements of these kind of life. Of course, another very important aspect is also if we assume an independent evolution on Mars; evolution is a random process, so it’s this funny combination of random changes, meeting reality, so to say, and then it’s elects for or against, mainly against a property, and then, you start out with the new property, with the new organism that has made these changes. I mean, we know that, well now with Corona, we are all experts in evolution, with all the variants that we have to deal with. So this-

Mikkel:

And this is not a linear process as well.

Kai:

It’s not a linear process.

Mikkel:

It’s more like a network kind of process where-

Kai:

Yeah. And when you take micrograms, they have of course their own genome, which changes due to random mutations, but they can also acquire genes from other microorganisms. So, it’s what’s called horizontal gene transfer, so one microorganism loses genes, so to say, when it dies, and another microorganism randomly can take them up and integrate them into its own genome, and then has new genes to work with. So this is common, pretty clever. Yeah. That’s how life, I mean, you have this linear type of evolution, but you also have evolution that goes across-

Mikkel:

Bridges.

Kai:

Yeah, crosses lineages.

Mikkel:

Okay. In my research, I’ve stumbled on the term extremophiles. Extremophiles which is, can you explain a little bit about that?

Kai:

I mean, that’s what we just talked about. Extremophiles are organisms that are living in what we consider an extreme environment. And that can be anything. I mean, we have extreme environments on our skin, for example. So we have areas which are dry, and we have areas which are relatively humid. And when you look into that, you will see that different organisms live on different parts of the skin. So a typical extreme environment would be the salt pans that you described in Bolivia, or the Atacama desert, which is also in South America, a bit more to the South, these dry valleys, but also the atmosphere is an extreme environment.

Mikkel:

So it’s basically just something that is not Denmark.

Kai:

I don’t know.

Mikkel:

Or you know –

Kai:

I know a lot of people for whom Denmark is quite extreme. Talk to people that come from Southern Europe or from Africa, that’s they think Denmark is quite an extreme place.

Mikkel:

Cold and rainy like today.

Kai:

And dark.

Mikkel:

Yeah. Dark. Yeah. That is true. That is actually true. I’m thinking, where does the research take you now? What are you looking into in the future? Because one of the things that I was quite excited about was the James Webb telescope coming up. Was it in December, I think? Or last-

Kai:

Yeah, I think now it’s in place, and I haven’t heard anything negative, so I think it’s working well.

Mikkel:

No, I just read about it and it is now fully unfolded, and with all those possible, I think was 300 potential errors, something that could go wrong. And it’s now fully unfolded, and I guess up and running, which is quite amazing. And that also means that it’s also in place, because it had to travel quite a distance before it arrived at the location. And is that something that you can use in your research?

Kai:

No, not really. I mean, it will give extremely interesting results, but it’s not yet there where you could look at a planet of Earth’s size. You could study, you can get a much better picture of the types of planets that are out there, but it’s not good enough, for example, to look at atmospheres of an Earth-like planet. You could study Neptune size planets or Jupiter size planets. That gets a lot of information about these kinds of planets.

Mikkel:

Is that because Earth size planets are basically too small to see?

Kai:

Yeah. And when you think about how tiny the atmosphere is compared to the planets’ diameter, and the information you get is the information that is carried by the light that has been shining through the atmosphere. So it’s the light coming from the star shining to the atmosphere, and this is what you catch with your mirrors, and then analyze it. And the bigger the atmosphere, the more likely it is to get information, to get some results. And the bigger the planet, I mean, Jupiter has a much bigger, thicker atmosphere, or bigger atmosphere than Earth has, so it’s much easier to study these kinds of planets.

Mikkel:

But is life most likely on Earthlike planets, or doesn’t that matter too much?

Kai:

I mean, we know at least that life is on Earthlike planets, so, and I think it, I would say-

Mikkel:

But is it a perfect place for life?

Kai:

I think so. I couldn’t think of a better place, for me at least.

Mikkel:

Okay.

Kai:

But of course, I mean it depends on, again, considering evolution, that evolution has to confront itself with the situation. So if it’s a bigger planet, more gravity a lot of things different

Mikkel:

But then again, you also have life at the bottom of the ocean where the pressure is so much higher, so-

Kai:

Yeah.

Mikkel:

So gravity would be something that evolution equals out somehow, right?

Kai:

Yeah. I mean, I think it’s not unlikely, but what we are looking for when people are claiming, “Okay, now we have found something exciting,” it’s usually an Earthlike planet they’re looking at. Because you need to have the right type of star also. I mean, we have already found multi-planetary systems, like the TRAPPIST system, for example, where you have, I think, seven different planets, and three or four of them are in the habitable zone of that star. And it’s a very different system; it’s an M dwarf, so the whole system is much smaller. The star is not so bright, so it’s easier to observe. These are systems that can be observed. But the question is, of course-

Mikkel:

And would you say it’s not so bright, so it’s easier to observe is that because a very bright star would kind of shine too… Or blind the cameras or-

Kai:

Yeah, I think it would be difficult to see it. And the other thing, the other advantage also, the way how we observe these planets is, they are circulating around the star. And for Earth, it takes a year as we know, so if we want to study Earth, it’s-

Mikkel:

Only once a year.

Kai:

Yeah. We look into the atmosphere. There’s only limited number of days that we can study it. And just to find out whether there’s a planet, you have to confirm it; it’s not just when you detect it the first time that you already can be sure that it’s a planet you have to-

Mikkel:

Yeah. And with Earth, you would have to wait for a year.

Kai:

Yeah, another year, maybe three years or four years before you can be sure that the dip that you see, I mean, what you look for is kind of the shadow of Earth, so that the light coming from the star is reduced because of the planet passing in front of it. So, this is not just a very clear picture; you get a lot of data, you have to clean the data, and then interpret them so that you can see, “Okay, there is actually a dip.”

Mikkel:

When I did my research, it sounded easier.

Kai:

Yeah. I mean, I’m just telling stories because that’s what I heard from the astronomers. I’m not an astronomer. Yeah. Yeah. So if you really want to understand, and get a good feeling about how complicated it is, and how much data massage and analysis they need to do in order to get the results, you need to talk to an astronomer. Shouldn’t talk to a microbiologist.

Mikkel:

No, I guess.

Kai:

But I mean, what I know, and what I learned from the astronomers is that with the James Webb telescope, we get one step further, but it’s not yet the type of telescope that you would need, or that is good enough to study the planets that would be interesting, in order to find, and to do this-

Mikkel:

What it does is just identifying the planets.

Kai:

But it could also do analysis, but it has to be a bigger planet. And I’m sure astronomers, they will come up with very interesting observations. And so, I mean, for the discovery of life, it’s not the good enough telescope. When it took 20 years or so to build the James Webb, So the next generation is-

Mikkel:

Also just imagine if we continue to accelerate the technological development, imagine in 20 years what that telescope will be able to do. Right? 20 years ago, we didn’t have an iPhone. Right?

Kai:

Yeah. Of course. I mean, a lot will happen. And I mean, this is also what the astronomists are waiting for, for the next generation.

Mikkel:

But, coming back to your field of study then, what are you looking forward to and what do you think will be the next big thing in your field of study?

Kai:

I mean-

Mikkel:

Astrobiology?

Kai:

Yeah. I mean, there’s a mission planned from the European Space Agency, an ExoMars mission that has, like James Webb, been on and off for almost 20 years. And the plan, it was to be sent, you can only send it every second year because then, it has to do something with the constellation, so the position of Earth and Mars, and to have the shortest traveling time.

Mikkel:

The Chinese, they missed an opportunity to send their rover to Mars, right?

Kai:

Yeah.

Mikkel:

They missed it by a day or two. So they had to wait for a year or two years.

Kai:

I didn’t hear that. But for the Europeans as well, so that they had to wait for two years and it, the plan is to send it in summer. Now the-

Mikkel:

In the coming up summer?

Kai:

Yeah. The big issue is now the whole Ukraine story. So, how that would affect, or will affect whether it’s going to be sent or not. So the people that are working on it and have been working on it for many years, they’re of course, quite anxious and afraid that it will not happen because of this.

Mikkel:

Of course. Is there any Danish contributions to this?

Kai:

Is there a Danish contribution to that? I’m not sure. There’s a contribution to the Perseverance, to the one that has just been sent. I’m not sure whether there is one to the ExoMars.

Mikkel:

What is it that this mission is going to yield of results?

Kai:

Yeah, what is interesting is until now we have only been taking samples from the very surface, maybe drilling in rock, 20 centimeter or so, but the idea with the ExoMars is that it can drill two meters into the Regolith. And this is just about-

Mikkel:

And this is the soil, the surface soil.

Kai:

And this is just about underneath where, I mean, you have all these different kinds of radiation; you have UV radiation, you have Gamma radiation, different types. So, they have a penetration depth to certain depth, so to say, and with this drill of two meters, you are just underneath, so you’re in a safe area. And the idea is that what has been affected by radiation could have been destroyed because radiation is energetic; it can destroy organic molecules. And when you get out of it, you have a fair chance of finding material that has been not affected by radiation, and has maybe been preserved there for many, many billion years. Three, four, five-

Mikkel:

Must be super exciting for you.

Kai:

Yeah. Of course. I mean, this is really what we are waiting for; to get deeper. The problem is hopefully it works. It’s not trivial to drill, even though it’s only two meters, so that has to work. You also have to get the material out of the drill, and then analyze it. So the machinery has to work to analyze not just enough to have the material, you also have to be able to analyze it. And there are always things that can go wrong. But I mean, I think this is really the most promising mission for now. There’s this Perseverance mission when they take small cores, the idea is then to pack them into containers. And it’s a three step mission, so to speak, because the idea with this is to bring material to Earth and-

Mikkel:

With the European mission.

Kai:

No, no, with the American mission. There are two American missions now; it’s the Curiosity and the Perseverance mission. And one of the major tasks is to collect material, to pack it-

Mikkel:

Yeah, to bring it back.

Kai:

No, they don’t bring it back; they just pack it, and then you have a next mission, and they collect it and put it in a kind of-

Mikkel:

Box.

Kai:

Rocket, whatever you call it. And then they shoot it into an orbit. And in the orbit, you have a satellite waiting to collect it and return it to Earth. So a lot of things can go wrong. And this should happen within the next 10 years or so, but space missions and 10 years can easily be 15 years. You never know. It’s also a question of-

Mikkel:

It’s also a question of funding

Kai:

Yeah. Of the political situation.

Mikkel:

Political interest.

Kai:

I mean, in 2000, it was said that in 2030, they will put people on Mars. We are far away from putting people on Mars.

Mikkel:

Yes, it seems far away.

Kai:

We don’t have spacecrafts and nothing yet in place. So that will take a long time before, if at all, people will be put on Mars, but these robotic missions, they are very promising. And I’m particularly excited about the ExoMars mission and hope… I mean, Europe has not a good record for exploring Mars. It’s okay when it comes to satellites, but they didn’t succeed in putting anything on Mars yet. Only the Americans that have been successful.

Mikkel:

Yeah. Wow. Super exciting. Now time’s running, and just to round off, I want to ask you where listeners can follow you in your research, but also maybe find out more about this topic. Is there any place you’d recommend?

Kai:

Yeah. I mean, a very good place to look is NASA’s homepage. They have exceptionally good outreach material. You can read about all the different missions, follow up on that. They have material for all ages, all interests, all levels of knowledge, this is really a place to go. For my own research, I don’t have a Twitter account or homepage, so I have one which is at Aarhus University, so you could just look up my name and then find whatever I’ve published. Otherwise you can just call me.

Mikkel:

Yeah. We’ll definitely link to that in the show notes. All right, Kai Finster, thank you so much for coming. And to you, dear listener, if you like podcast, help us spread it by subscribing of course, and liking if you like it and sharing it, of course, with your friends and family. And like I said, anything that we talked about now, you could find links to this in the show notes, and the show notes, you’ll find on our website, which is montanus.co, and that is, C-O without the M, so montanus.co/bigideasonly, and that is it for now. Thank you so much for coming and thank you so much for listening.

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