Astrobiological Media

by Melody Jue Madelyn Broome

Ethics and Astrobiology is a collaborative project emerging from a reading group that explores astrobiological research on a temporal scale: what life was, what life is, and what life could be across the cosmos. In the gatherings of this reading group, the collaborators leveraged the interdisciplinary friction generated by thinking through such queries together as an occasion to create a space for ethical reflection. What follows in this series is an attempt to capture some of that intellectual magic for a broader audience.

In May 2023, Melody joined Ethics and Astrobiology participant Madelyn Broome and co-facilitator Zac Zimmer in conversation about media, water worlds, and astrobiology. Melody Jue’s book Wild Blue Media: Thinking Through Seawater was featured on the Ethics and Astrobiology reading list. Melody’s book is an example of media-specific analysis, which the group found quite helpful as a model for thinking through the media of space telescopes like the James Webb Space Telescope (JWST). 

Zac Zimmer: Melody, do you have a basic definition of milieu-specific analysis that you can give? And then we can open up to the question about what astrobiology as a field needs to know about media and milieu, and how something like milieu-specific analysis can translate or travel to space? 

Melody Jue: I can begin with how I was thinking about it, but I’m curious to see how the concept of milieu-specific analysis travels for Maddy and for the reading group. It makes me really happy to hear that it has traveled for the group, because the whole idea behind the book was to think through the oceans as a case study for identifying areas of terrestrial bias that have come to dominate the way we formulate concepts, in ways that structure what we take for granted about orientation. This is why I cite David Valentine, the space ethnographer, especially his reflections on the way that one would orient differently in outer space. The conditions of gravity are different. It’s not a coincidence that NASA trains astronauts in the ocean! NASA’s Extreme Environment Mission Operations (NEEMO) trains at the Aquarius Reef Base in Florida for two main reasons. First, the lessening of gravity one experiences by spending time in the ocean, but also being in an environment where one has to be hermetically sealed with an air supply. But of course, the big difference is pressure. In the ocean, divers have to deal with variations and increasing pressure in the ocean, whereas in space, astronauts can have a much lighter suit because it doesn’t have to protect from the larger crushing pressures of deep waters. 

There have been humanities scholars before who had pointed out a kind of terrestrial bias, like Dan Brayton, and often this occurred at the level of nouns, conceptual terminology that would describe the ocean in terrestrial terms. You can see this in the naming of ocean creatures: sea hair, sea lettuce, bat ray…there are so many terrestrial animal analogies that get mapped onto a taxonomy of sea creatures. What initially struck me in reading Vilém Flusser’s “fictional science text” on Vampyroteuthis infernalis, or the vampire squid, is that he was doing two interesting things. One was imagining specifically what kind of philosophy would the vampire squid be capable of producing? And then imagining how this would take place under the squid’s particular circumstances—more specifically, the strange embodiment of the vampire squid, and also in the context of the deep sea. That was the first chapter I wrote, even though it comes second in the book. And it was the place where I developed a sense of how one could pay attention to these dual factors of embodiment and environment to ask questions like: what are normative ways of orienting within an embodied physicality within the particular affordances of a milieu like the deep sea? 

And what this calls into question was not only nouns, but specifically prepositions. Prepositions are orienting words, either within space or within time or within a kind of abstract relation that connotes forms of orientation. Following the work of Lakoff and Johnson on embodied metaphor and orientational metaphors, the chapter asks questions like, what would up and down mean to a floating organism? And that’s a fair question that could also be asked in outer space. What milieu-specific analysis does is take into consideration both embodiment and environment, in order to address the difference between the ways we reflexively might try to describe something, and the actual affordances of the environments that it’s in. This is a question you could ask of the vampire squid, but it can easily extend to machine technologies as well, like the question of the normative milieu of a satellite, for example. This has to do with what kind of environment the satellite is expecting to be in, and how does perception take place within that environment? This is another way of asking about the Ümwelt or sensory world of the machine or the apparatus. That concept, ümwelt, is coming from Jakob von Uexküll, who has had a popular resurgence in the 2010s as someone who was thinking about animals and the particularities of animal sensory worlds. 

Later in the book I also think about the conditions of inscription in the ocean. I found so many instances of the ocean being described as a database, or information storage technologies described through liquid metaphors of surfing the web and flows of data. But the ocean is constantly in movement, and therefore is a very different kind of archival medium than the geologic strata or a computer database! I became fascinated with the abstraction of liquidity going on in all of those metaphors.

I think that the lesson I was hoping to model was to simply ask: what kinds of habits of perception and orientation are we bringing to particular environments, and how might that contrast if you think carefully with the unique qualities of those environments? I’m curious to see what Madelyn thinks about how this applies in space: what are the salient qualities of the milieu that the JSWT finds itself in, especially those qualities that we’re not habituated to anticipate, but that one finds out through lots of trial and error, through simply putting the thing up there? Maybe it’s radiation, maybe it’s something else. You can ask these questions about extraterrestrial worlds too: what are the qualities that come to matter? And what are the media of perception? 

This image shows NGC 6822, which lies about 1.5 million light-years away and is one of the Milky Way’s nearest galactic neighbors. This is a composite image of data captured by two instruments aboard the JWST, the MIRI and the NIRCam. For a comparison between the two, and further explanation, see this slider tool. “The Life and Times of Dust.” Credit: ESA/Webb, NASA & CSA, M. Meixner.

So to return to the question about what astrobiology needs to know about media: it’s an important question, but one that I’m not in the best position to answer. But I could rephrase it like this: what are the conditions of mediation that astrobiology needs to know about? Or what are the conditions of mediation via different kinds of sensing apparatuses that are important within astrobiology, and what are the capabilities and also the limitations of those? What are they really good at? What do they not ask or not anticipate? Those are all very science and technology (STS) questions that can be explored in much more detail.

Madelyn Broome: You touched on everything that I wanted to highlight in Wild Blue Media, themes of orientation in space, pressure, the terrestrial bias, and different ways of mediation. Let’s start with terrestrial bias, because as soon as you mentioned that, a new thought occurred to me that I hadn’t explored before, which is actually three things: terrestrial bias is necessary, terrestrial bias is limiting, and terrestrial bias is powerful. The reason I say it’s necessary when we’re looking outwards, specifically in an astrobiological context, is that “Life As We Know It” (LAWKI) without the terrestrial bias, without the context of the grounding that we use to define life as something we recognize, something that operates under similar environments, something that has similar biological processes, simply does not exist. LAWKI gives off recognizable signatures, what we call biosignatures, signs of being there. 

Without those parameters, without the confinement that such bias presents, we have an infinite parameter space. How do you look for something in an infinite parameter space? I like to describe trying to define “Life As We Don’t Know It” as trying to describe a color that you don’t know exists. Trying to describe a color you’ve never seen before. Without that terrestrial grounding, we have no way to constrain the search for life. That’s why terrestrial bias is necessary. As for why terrestrial bias is limiting, that’s the entire point of your book! 

But the third part, as to why terrestrial bias is powerful: that terrestrial bias is what gives us metaphor. I absolutely adored where you brought up the tapir in Viveiros De Castro, this idea that the muddy watering hole is seen by tapirs as a great ceremonial house. This really exemplifies the idea that even in different orientations, when you have shared environments or shared experience, you can reorient yourself through the use of metaphor. So Viveiros de Castro points out that to us, what is a muddy water hole is to a tapir, a great ceremonial house. That’s why I think that terrestrial bias gives us the ground, a reference point. And this reference point is where we can launch into metaphor that opens up that infinite parameter space, so we can describe pretty much anything using these references. 

MJ: I think that’s really nicely put. And the idea of a reference point is so key. It relates strongly to the feminist science studies commitment to the importance of situatedness which I also try to channel in the book. There’s a close relation there between one’s reference point and the scientist’s situatedness. Perspectives always come from somewhere! They are necessary and they are limiting, but they’re also the point from which you can extend outwards and imagine otherwise. But even the language one uses to describe reference points as foundational or grounding, these are also terrestrial metaphors. And so what reference points do, what’s the mobility of a reference point, could also be a question to play with if one imagines aerial or liquid reference points or something that’s not necessarily tied to a sense of stability, too. 

Reorientations and Reference Points

MB: I wonder if we as humans are able to ever truly reorient ourselves if we’re put into this other medium? Or do we always need some sort of grounding, some sort of reference point? This connects to proprioception, our sense of where we are in space. And that’s very important for how we orient ourselves and also literally how we construct everything and define our language and culture, to your point. But what happens when that’s gone? This is a problem that NASA has investigated, and I want to share a quote from an article on what happens to people in space. And it reads: 

“On Earth, your vestibular or balance system tells you how your head moves relative to gravity, but in space, the gravity reference is gone. That causes these perceptual illusions, as well as difficulty coordinating the movement of the eyes and the head.”

And the point of this article was that weirdly enough, astronauts get used to that. And they can even have trouble going back to gravity and reorienting themselves relative to that. And yet we still build everything we build in space, space stations and everything in them, with reference to a linear bias, a linear way of thinking. So up and down in the space station as a top and a bottom, you walk on a treadmill that is some simulation of gravity, etc. It turns out that the astronauts are never completely removed from the Earth, or completely reoriented. But they do learn to reorient to existence in space to the point where they have trouble going back to the original, terrestrial orientation. I thought that was fascinating!

MJ: What you mentioned with the astronauts reminds me of other examples, too, where one carries the embodied memory of motion. I’m not a skier, but I’ve gone just a handful of times, and the feeling that you’re still in motion afterwards when you’re sitting in the car, the memory of that stays with you. Or in the ocean example, having what’s called dock rock, where you’re still swaying on the dock because you’re anticipating a boat moving beneath you. 

MB: Embodied memory! So it seems to be based on what you were exploring in your book, the idea of habit and habitats. 

MJ: Yes, so true. It’s heavily context dependent. The other context to Wild Blue Media that was always at the back of my mind, even if it wasn’t coming clearly forward, was the practice of comparison, either comparative literature or, following N. Katherine Hayles, comparative media studies. This is the question of one’s familiar reference or reference points, and the matter of shuttling, translating or transducing between two or more such frames. This is where both the question of translation and the question of ethnography necessarily come into the picture, where the observer becomes self-conscious about what they bring to observations of something that’s outside the realm of the familiar. 

MB: And the innate human desire to feed it back through the familiar, which can be empowering and can also be limiting. 

MJ: I tried to think about this in the preface to Wild Blue Media, “Into the Blue.” You need somewhere to start, and that’s often the place one ends up, but it’s absolutely a question of the reference point where one begins. 

MB: That’s a perfect way to describe the search for life as we know it: LAWKI is a starting point, and we may discover things that are not life as we know it and that’s when we need those interpretive frameworks. That’s when the science side of this comes in: what data do we need? A question that your entire book brought up is: is there an unalterable, undeniable universal language? The answer for astronomers would be, yes, light, and electromagnetic radiation in all its different flavors, these wavelengths of light carry information. That’s how we perceive this world. That’s the best way that we know about distant exoplanets. Scientists can use more inscriptive methods; for example, we use asteroids to infer things about the makeup of rocks and water delivery in our own solar system. But for the most part, the information that we are getting comes from light. Now is light truly, objectively unbiased? Is it unaltered? It’s not. And in fact, the impurities that come in light actually tell us a lot. That’s what spectra are. Spectra is a collection of wavelengths of light. And when we look at a pure white light source, we make a spectrum of it. We plot every single wavelength that is coming from that pure white light: this looks like a rainbow.

Transit spectroscopy is the method used by JWST to detect and analyze planetary atmospheres, and is currently one of the best ways to remotely determine whether or not a given exoplanet might support biological life. “Exoplanet WASP-96 b (NIRISS Transit Light Curve).” Credit: NASA, ESA, CSA, STScI.

Now, what happens when it’s not a pure white light? What happens when something is in front of that white light, like a gas? Or what happens when it is in fact not a white light we’re looking at, but a planet with lots of complexities in its atmosphere? That means when that light comes to us, it’s no longer pure and unaltered. It is missing things in a very significant way. And it is those impurities, those lacks of light at certain wavelengths, or the excess of light at other wavelengths, that tells us that a molecule or atom is there. That’s how we infer the chemical makeup of these planets and their atmospheres. That’s how we infer what is between us and those planets, those sources of light. But when it comes to us, it is altered, but it is still coming direct. We then have to add a layer of interpretation on it. 

And that’s where things get really interesting. You have the interpretation through the telescope itself: we’ve received all this light information, but what do we think is actually happening here? And when we all agree that a given element is present on this planet, then what does that mean? That is in fact one of the big questions of astrobiology right now is, what are biosignatures? What are elements and compounds and molecules we could see in the atmosphere of a planet that would definitely indicate Life As We Know It and not something else? So even if you observe this information, you still have layers of interpretation on top of it, it comes through space and it’s interfered with, it comes through the telescope and is interfered with, and it comes through human interpretation and it is interfered with. Even though we see the world very, very differently with our plain eyes, we have these telescopes that allow us to explore life far beyond what our human eyes can see. 

And that’s why the Mantis Shrimp is so interesting. The Mantis Shrimp can see many more wavelengths of light than we can. It sees colors that we simply can’t imagine. And while we will never be able to imagine those colors and truly reorient ourselves to the Mantis Shrimp’s perception of reality, we have tools like the telescopes and spectra of light that allow us to plot our own terrestrial framework, make sense of all these wavelengths of light that we can’t see. We can get information from light we cannot see! And in fact, that is where the richest information is, outside of the optical range of what we can see with our eyes, which must be graphed or plotted in some sort of way so we can interpret it.

MJ: I think this is so fascinating. The analogy to think of light as a language, which is also a metaphor with similarities and differences, opens up the question of interpretation, too. Correct me if I’m wrong here, but it sounds like there’s a whole question of whether what’s missing is…what was the word you used? Not disturbance, the artifact, whether that’s a meaningful biosignature or whether it’s extraneous and caused by some interpretive flaw. That seems difficult to negotiate. 

MB: Oh my goodness. It’s a whole field! That’s what Natalie Batalha does here at Santa Cruz: looking at spectra of these planets and interpreting potential biosignatures. And it is still so uncertain, even with the new results that are coming from JWST. 

MJ: What are some examples of biosignatures? 

MB: The most common one we care about is water. Water is not a biosignature in that it comes from life. It’s just something we look for in order for there to be life, because life as we know it requires water. Other biosignatures include specific chemicals, specific molecules that could only be made by life processes. Specifically, there is chemical disequilibrium, there is more or less of it than could be produced by geological and atmospheric processes alone. One example is the phosphine on Venus. This finding got all the headline attention because there was definitely too much phosphine, allegedly, on Venus. This is a great example of an interpretive framework, because someone took a look at that spectrum. And it’s not just that light comes from space, perfect and unaltered, hits the telescope and voila, we have the answer. No, we have to reduce this data. We have to massage it, using scientific methods to get something readable out of it. 

And so when the scientists reduced the data coming from Venus, they did it in such a way that the signal popped out. It looked like there was much more phosphine than there should have been. Now, phosphine in particular is something that can’t be made by geological processes, in the amount that we saw, it would have to come from something metabolizing. And so that excess of reported phosphine was an enormous, very clear biosignature: it has to come from life, it can’t come from anything else. But in fact it wasn’t a very clear biosignature. Because of that layer of interpretation that went into the choices made to scale these signals, that is what led this to be most likely a false positive. And other scientists have since gone back and said, nope, this is not a signal that is significant enough to say anything definitive. This doesn’t mean it’s dead in the water, it just means that we need to go back, we need to get more of this light information coming from this planet and do better interpretation. 

Atmospheric characteristics of an exoplanet indicating the presence of water in the atmosphere. “Exoplanet WASP-96 b Atmosphere Composition.” Credit: NASA, ESA, CSA, STScI.

MJ: What’s exciting to you right now about JWST and where it’s looking and what’s coming back from it?

MB: Well, I’m very excited to look back to the beginnings of the universe further than we’ve ever seen before, but as for astrobiology specifically, it’s these signals that are coming from atmospheres, specifically when we’re able to determine whether or not planets have water. That is actually a recent result that was published as some of these first spectra. The teams chose very specifically exoplanet candidates they thought had water, and when they looked at them, the signal does indeed show that it probably does have something akin to water. And this is just a first step in being able to determine which planets can host life. 

Terrestrial, Planetary, and Solar System Mimesis

ZZ: Wild Blue Media proposes that situating our knowledge within the ocean can shift our perspective away from our natural inclination towards what Melody calls “terrestrial mimesis.” We have already spoken a bit about this, how our terrestrial bias creeps into our understanding of ocean life, and we lose the milieu-specificity of ocean life when we constantly compare it with what happens on land, outside of the pressure and fluidity of the ocean medium. We see something analogous in the popular conversations about exoplanets. We have these names like Super Earth for entire categories of exoplanets. And I think one of the things that might be happening is that as we put these space telescopes further and further out beyond the realm, looking out of the solar system, the concept of terrestrial mimesis might actually expand to a solar system mimesis. 

MB: I was going to bring up that same question! We don’t just talk about Super Earth, we talk about Sub-Neptunes and Hot Jupiters. And we use our solar system as a reference point to determine whether we are very strange as a solar system, or whether we are factoring normal as a solar system, a question we can’t quite answer yet, but is very intriguing and a Copernican Revolution in reorienting our sense of importance and our sense of place. 

This image, from JWST’s NIRCam, is a near-infrared picture of the irregular galaxy NGC 6822. It shows a densely-packed field of stars with dark, wispy red gas. “NGC 6822.” Credit: ESA/Webb, NASA & CSA, M. Meixner.

MJ: I hadn’t thought of it at that scale yet. But yes, I guess the solar system is the next unit of questioning, again, what references we expect to find elsewhere. We can compare it to what’s near Earth here. Hmm, wow. 

MB: Astronomers are pretty good at that. We do that a lot. When we talk about other galaxies, we’re comparing them to our own Milky Way. When we talk about other galaxy clusters or groups of galaxies that are gravitationally grouped together, we look at our own galaxy cluster to understand that. And so we are oftentimes as astronomers transposing ourselves to these different spaces. It makes sense on a practical level because there’s more information available about the systems that we’re either part of or closer to. 

I think that there’s also something interesting to be said about light too. Light is not only altered because it passes through things, it’s altered by the distance it travels. The further away something is, the more redshifted the light is. And the reason it’s called redshift is because longer wavelengths of light are redder, shorter wavelengths are bluer. And so as a wavelength of light passes through time, passes through space—there’s two forms of this—but the one that corresponds to distance is the fact that the space between any two objects in the universe is expanding. Every point in the universe is expanding at all times. And that expansion is accelerating, which is fascinating and terrifying. But as space expands between these two points, the wavelength of light that was traveling through it is stretched to longer and longer wavelengths. This is like when you’ve got a string tied to a fixed point, and you’re waving it and you start to walk further away, the waves are going to become slower and longer. So that happens when light travels to us from great distances. 

This infographic of an Einstein ring shows what Broome describes in how distance alters the perceived color of wavelengths. The foreground galaxy appears blue while the most distant galaxy is red. “What Creates an Einstein Ring?” Credit: S. Doyle/J. Spilker, James Webb Space Telescope.

This is why time and distance become synonymous in astronomy, in a way that makes your interesting exploration of volume literally another dimension. And the dimension of time is tied to the idea of volume because when you look further out in space, you’re looking further back in time. And that’s because light travels at a finite speed. So we can only see things that have been traveling to us for 13.7 billion years, or the age of the universe. We can only see things that are 13.7 billion light years away, no further. That’s the temporal limit on what we will ever know. And that in fact can be another dimension—in addition to embodiment, shared sensorium and orientation—is this idea of temporality too, because what do we do if we come across a species that has an entirely different conception of temporality? 

We also have the very basic issue of getting signals from other places: the speed of light is the limit. We’ve sent out radio waves into space, and we’re looking for radio waves sent to us, but those radio waves that the Search for Extraterrestrial Intelligence (SETI) is looking for are going to be coming from beyond the nearest planet which is around 4.5 light years away. Alpha and Proxima Centauri have a planet. And so the closest sources of exoplanet light are a minimum of 4.5 years old, nevermind all these interfering effects and other things going on. And so there’s always going to be that aspect of delay and time, more a distemporality. I don’t really have a word for it.

ZZ: I’ll use the question of vocabulary to shift our conversation to the question of polysemy, which has been an on-going theme for our reading group. Polysemy was one of the profound challenges in the first few meetings, and we came up with a shorthand to address what we called “red flag words” in our group, because otherwise we just ended up talking across each other, especially with words that had very specific technical definitions.

MB: As astrobiologists, we’re used to dealing with polysemy all the time. And that’s my argument, that there is a great need in astrobiology for a polysemantic interpretive framework. We all have different orientations, and we bring our own fields and disciplines to this, while also creating new constructs as research goes in new directions and describes realities that never would have been imagined before. But polysemy is also a very literal problem because when I say metals as an astronomer, I mean literally every element that is not hydrogen or helium. But when a chemist says metals, they mean elements like iron and tin and aluminum, so there is a communication barrier that exists for us, where polysemy allows us to explore and create, but also it makes it very difficult to communicate. Without a shared lexicon, we’re in trouble! 

MJ: I’ve also been in conversations in mixed rooms of oceanographers, artists and humanists together. It’s fascinating to see which words are understood in divergent ways, and conversely which words don’t pose those challenges. The one that surprised me is “agency.” I remember as an undergraduate first studying literature, I struggled with the idea of the “agency” of a character, because there’s a bit of a learning threshold to figure out what such a key vocabulary word within literary analysis means. And it turns out the scientists were just fine thinking about agency in the context of an experiment. That one surprised me, that “agency” communicated easily. It’s reminding me of the classic philosophy of science text, Thomas Kuhn’s Structure of Scientific Revolution, because it also talks about differences in language and vocabulary being thresholds where people are not quite understanding each other, and paradigm shifts emerge when these different understandings of vocabulary reach a breaking point. So communication is not seamless, and the differences in technical meanings matter, but also on the cultural side, too. 

I think a lot about how coral is described as a colonial organism. Anna Elias has written an amazing book, Coral Empire, which delves into figurations of empire via corals that explode many taken-for-granted technical formulations of the colonial as the plural or the multiple. What’s fascinating is that all these conversations happen through polysemy, but also mostly in English, which gets taken for granted, too! One thing I was very conscious of in Wild Blue Media was the question of how much polysemy a concept can bear within one language, because it’s going to change very much in another. Once again I want to be careful here not to be too noun-based, in order to think of all of the parts of speech that carry different polysemy or valances. So that’s the other step, too, in thinking comparatively. I think my field has an implicit English bias, especially in philosophy and critical theory, or at least a Western bias, where words and especially nouns are made to bear quite a bit of the language of science. 

MB: I will say, before we move on, your problem of colonization is one that space deals very much with. It is exactly this: the language of colonization and the image of space expanding outwards.

ZZ: Yes, the frontier concept is a constant sticking point, and one of the things that has come out of our group for the scientists who do public presentations of their space research is an understanding of the power that those metaphors play in framing concepts. It’s important because there’s an attitude, like oh stop language policing stuff doesn’t really matter, which I think the three of us understand is not the case. It matters so much! But it’s challenging; that’s why this coral book will end up on our reading list, so thank you!

MJ: Yeah I have another recommendation, too. The first chapter of Hi’ilei Hobart’s Cooling the Tropics was really good, and I know a very sensitive issue across colonization or colonialism and astrobiology is the telescope question. Hobart’s chapter looks at the characterization of Mauna Kea as a Mars analog, as a space analog, and the way that that characterization is a precondition for the settler colonial move of saying this is empty therefore we can build, even though of course it has prior historical significance and sacredness in the traditions of the people who had made Hawai’i home for thousands of years. I think that chapter is extremely well written and also helpful for looking at why emptiness has always been a precondition for colonization.

MB: That is really interesting when it comes to looking outward, because the idea of space as empty is prevalent. It’s part of the reason we are such a metaphorical field, and why we have to be so careful about the language we use, because people have very little direct contact with the things we study. I don’t want to assume anything about communicating ocean science, but many people have seen an ocean, they can touch an ocean, probably they’ve been in an ocean at least, or they’ve eaten products from it. When it comes to space, we increasingly have little to no direct contact with space, dark skies are disappearing, and there’s a delay in the information that comes from space. It has to go through these layers of interpretation which are both telescopic and human layers of interpretation. So telescopes aren’t without politics. Weirdly I would say that perhaps the most immediate connection folks have to space anymore is aliens, representations of science fiction and the alien.

Pressure and Oceans

MB: Water worlds are the hot ticket item right now, because we’re beginning to have discoveries that may or may not indicate there are water worlds out there. But regardless of how we find them, we theorize they should exist because of models of how these planets are forming. To be clear we are not talking about Earth; Earth is not a water world despite being 70% water, because it is about 0.05 percent water by mass. These water worlds we’re talking about are up to 50-70 percent water by mass.

MJ: Wow!

MB: Imagining a planet that is that massive, with that much water, the pressure becomes immense, unimaginable even. Water at the base of these oceans is probably in a supercritical form, so it’s no longer gas, it is no longer liquid water. The pressure and temperature is high enough that it is what we call supercritical water, which probably looks something like vapor. The pressure for water to go super critical is 2000 times the pressure of our own atmosphere at sea level (a unit we call “atmospheres”). That massive amount of pressure is mind-blowing. What is it at the base of the ocean?

MJ: One atmosphere is about 33 feet, so I go down to about three or four atmospheres of pressure at the most. And so you do the calculation for that on our world, and it’s really really deep…

MB: And the mind-blowing thing is that water is life, as far as we know it, but it’s unclear if life can survive on these water worlds. That’s the question I find myself asking.

We think of habitability as water, water in its liquid form, but in the case of these water worlds, water has actually transcended that form of liquid water into that supercritical state. But it appears that even on Earth, some bacterial life can survive at those insane pressures. Organisms have even been shown to survive pressures of more than 10,000 atmospheres.

MB: There’s so much more to be said about imagining alien life, how so much of that is rooted in what seems alien on our own planet, much of it is based on ocean creatures!

ZZ: We could keep this going for hours and hours! But before we close, I did want to flag one thing. Our group tends towards thinking about life and astrobiology beyond our own solar system, and one thing that we haven’t covered is the possibility for life off-earth but within the solar system. It struck me, one of the earlier things that you said Melody, talking about astronauts training in dive facilities in Florida, that one of the big divides in astrobiology is the split between remote observation versus presence. There’s no conceivable way for human beings to get out of the solar system, while there are potential paths to get humans to other planets in the solar system, and there are potential paths for sample return within the solar system. That’s also a very important difference to mark, that the conditions of mediation change at the scale of the solar system versus moving outside of the solar system.

MB: That’s my exoplanets bias, sorry.

Another image of the irregular galaxy NGC 6822. The brilliant blue gas indicates light emitted by organic compounds called polycyclic aromatic hydrocarbons, which play a critical role in the formation of stars and planets.This image only visualizes data captured by the MIRI instrument. ”NGC 6822 (MIRI image).” Credit: ESA/Webb, NASA & CSA, M. Meixner.

ZZ: That’s why the phosphine finding on Venus has conditions that go beyond the science, because in a sense it’s a certain threshold to see whether people are going to be making strong cases for space agencies to fund more intensive sample return missions to this particular place versus that particular place. That’s what I meant before with the idea that the conditions of mediation also become the conditions of science within bureaucracy and capital.

MJ: Absolutely. I just taught Naomi Oreskes’ book Science on a Mission in my oceanic forms class. Oreskes, a historian of science at Harvard, wrote a fascinating examination of funding in oceanography and its relation to military questions, which of course applies to space as well. She was exploring if the funding coming from the military determined the questions that were then considered valuable in science, and when were the scientists resistant to this, and when were they able to ask other questions, many permutations on case-by-case studies including some pretty amazing prehistory about the deep-ocean research submersible ALVIN, too, that I did not know about, like rescuing lost nuclear bombs on the seafloor. 

I wanted to mention one last thing, an artistic piece by Katie Paterson, that draws together some interesting questions around perception and embodiment. She imagined simulating a voyage through our solar system with a scented candle, so that as the candle burned it went through the different elements, representing different planets, as one might move through space. Of course this is a matter of impossible witnessing, because one can’t breathe in space, one can’t smell as one goes out of the solar system, so it’s impossible on an embodied and temporal level. That’s why I think this term “witnessing” matters here, and I haven’t figured out why or exactly how, but the observer or the witness is impossible because one could never in an unmediated way experience smell in outer space. 

There is another project I just worked on last summer with some art and science collaborators, on what it would be like to smell underwater, because we also can’t perceive that in an unmediated way, because of our necessity to breathe air. So we wrote a speculative fiction together exploring translating from smell to sound, because sound is similar in its dispersive effects and the questions of proximity, in the way that sound evokes texture and other things, so you could use sound to get to smell underwater through a translation moment.

Maybe this is helpful for a space context; we were thinking about synesthesia and the translation of senses, or the simultaneity of senses. And also the way that we see some creatures experiencing synesthesia in a way that’s normal for them, but we just call it that because we don’t have a term for senses that for us seem bifurcated or separate. Like crustaceans or octopuses who taste with their feet: for us taste and touch would usually be separate but they come together in these cases. So synesthesia could also be something to explore, too, for two things: the communication of the spectra, but also moments where maybe one can productively draw on the sensory vocabulary of a different mode in order to get at something else which is partial and never exact but nonetheless could be strategic and conveying things.

MB: Yes, synesthesia is a metaphor! And we have to do it: we do data sonification where we turn these wavelengths of light into wavelengths of sound and get enormous amounts of information from that, or we make art pieces out of them, and even the act of drawing these planets in artistic renditions is a form of synesthesia, translating from the light data that doesn’t come as data to our optical range but tells us what molecules are present there, and we translate back from that to a color that that molecule gives off.

ZZ: Such a beautiful way to conclude, getting back to this idea of a shared sensorium built through intentional synesthesia for communication beyond our own species and beyond our own planet. It’s really wonderful. Any final thoughts?

MB: I was reading about “amphibious” in your book, and it made me think we need a word for the human crossing that interface into space. 

MJ: So “amphibious” means “of two worlds.”

MB: So it should go both ways.

MJ: But it feels like there should be a more specific term, because it is a different interface, and ‘amphibious’ is already overlaid with the aquatic. 

ZZ: And it’s also the eternal question that we keep coming back to: should we reappropriate what we can understand as the original spirit of the word, meaning “between two worlds,” or has the concept been so saturated with the sea-shore interface that we can’t conceive of it otherwise and so we need something new?


This essay is part of the Ethics and Astrobiology series, funded by UCHRI’s Recasting the Humanities: Foundry Guest Editorship grant.

This publication was partially funded by the Andrew W. Mellon Foundation.