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Extremophilia: Ligia Fonseca Coelho is Shaping the Future of Astrobiology

Ligia Fonseca Coelho
Ligia Fonseca Coelho

Born in temperate Portugal, raised by a working single mother, Ligia Fonseca Coelho never went on winter break trips as a child, never flung snowballs or constructed snowmen, never learned to ice skate, sled, or ski. The first time she ever saw a snowflake, in fact, was on her first research expedition to the southeastern end of Hudson Bay.


“When it landed on my arm,” she giddily recalled, “I remember looking down and thinking, ‘Oh my God! Just like the cartoons—it’s a crystal star!’”


Ligia was standing just 10 degrees south of the Arctic Circle, on a thick slab of sea ice that locks up the water for most of the year. Snow was to be expected. Yet for her, that flake represented a revelation—not just a speck of seasonal precipitation, but a symbol of all that she had overcome to reach that point, 55.3°N at the mouth of the Great Whale River, and everything she still aspired to achieve.


“I was so happy,” she remembered. “To this day, I can’t get enough of snow.”


As an astrobiologist, Ligia has dedicated herself to the study of possible alien life on distant, icy worlds; and as a first-gen college kid from working-class Portugal, she found the Canadian Subarctic to be as distant and as alien as any frigid moon.


Hostile and exotic planes have populated Ligia’s imagination since her childhood, when her mother, a tenacious and hardworking woman, flooded her life with books, though she herself had neither time nor inclination to read. Unsure what kinds of books to give her daughter, she simply gave her everything, including books about space. These cast such a strong spell on Ligia that her mother soon became frightened.


“She used to tell me, ‘Ligia, please don’t become an astronaut,’” said Ligia. “‘Please, please don’t go to space. It’s very unsafe!’ Then she bought me more books so I could learn how dangerous space is!”


Instead of discouraging her, this only fueled Ligia’s passion: “In my little kid brain, I figured, ‘Well, if Mommy’s so afraid I’ll go to space, then it must be achievable!’ That’s how I grew up believing everything is possible.”


Now a Fulbright Schuman Scholar completing postdoctoral work at Cornell, Ligia grew up with few intellectual role models. Hardly any literate or educated adults shared her neighborhood. Yet she benefitted from a role model of a different kind: a mother tough and brave enough to extricate herself from an abusive marriage, savvy and diligent enough to single-handedly put food on the table, and perceptive enough to raise two very different children without neglecting their physical, emotional, or intellectual needs. Many of the traits that now define Ligia’s life and career are shared by her mother, including willingness to break away from the familiar and stake her claim in new terrain.


In school, Ligia’s courage was often misread. “I was labeled ‘aggressive,’” she remembered, “and ‘bossy.’” A girl who didn’t fit the mold, she loved math and science and was always voicing her opinions, always asking questions. “I wasn’t bossing anyone,” she said. “I saw the goals and wanted everyone to get there together. I was always thinking, ‘What can I do to make this happen?’”


In response, teachers and peers alike told Ligia to tone it down. For years, she tried. Every year, she made “tone it down” her New Year’s resolution, and every year, it didn’t work. “Sooner or later, I’d blurt something out,” she remembered, “and it was like, ‘Oops! Back to square one!’”


At home, her curiosity found more fertile soil. Her mother, though religious, never dismissed her existential ponderings with pat appeals to God, instead meeting questions like “Mommy, why does all this stuff exist?” by encouraging Ligia to study hard and learn. She seemed to take for granted that her daughter would achieve what she herself had not, excelling academically despite the obstacles—a stance that Ligia believes was instrumental.


“I think it’s really important for uneducated parents,” she observed, “not to treat their kids like education’s somehow out of reach. Say to them, ‘Why wouldn’t you go to school? Your context isn’t the same as my context. Your time isn’t the same as mine. Of course you can!’”


Yet it wasn’t until she got to college that Ligia experienced real support from an educational institution for the first time. “I had a mentor,” she said, “who told me I wasn’t being bossy, who said, ‘Actually, Ligia, this isn’t a problem. This is who you are.’ And I thought, ‘Oh, wow…this is who I am!’”


At the University of Lisbon, Ligia ended up studying biology instead of her true passion, astrophysics, because the program was comparatively affordable and close to home. Next, she earned an MS in microbiology at the same university, then embarked on a PhD in astrobiology and bioengineering, a collaboration between her alma mater and Cornell University, made possible by the MIT-Portugal Program. She might have remained in Portugal for her postdoctoral work as well if it weren’t for Dr. Lisa Kaltenegger of Cornell, who encouraged her to apply for the Fulbright.


“I hadn’t even finished my PhD,” said Ligia, “and the Portugal applications had just closed, so I had to apply through the EU, competing with all of Europe…but Lisa said I should, and here I am!”


Initially, she expected to finish her postdoc early, but her work yielded far more breakthroughs than anyone on the team anticipated, requiring more time to write up and publish the findings.


The purpose of Ligia's work is to study microorganisms that live in extreme locations, such as ice, and associated biological pigments, in particular carotenoids. These compounds, which only living organisms can produce, are common in extremophiles, for they offer protection from dryness, radiation, cold, and other harsh environmental features. When they’re present in sufficiently high concentrations, the coloration they produce can even be visible from space. According to a paper co-authored by Dr. Kaltenegger, the pigments that microorganisms produce on Earth may have been visible to hypothetical alien passersby for as many as two billion years. 


“The problem,” Ligia explained, “is that we haven’t yet assembled a comprehensive inventory of all the wavelengths reflected by these pigments under different conditions, nor have we translated the data we do have into the language of spectroscopy, which is what astronomers use.”

It’s possible, in other words, that astronomers have already glimpsed life on other worlds, but because they lacked specific points of reference derived from terrestrial sources, they didn’t know what they were looking at. If such points of reference are not established through careful study of terrestrial ecosystems, then future astronomers may easily miss the very signs of life they will have worked so hard to find.


This is one of the problems that Ligia has set out to solve.


Carotenoids reflect a vivid spectrum of pastels, shading from pink to red to orange to yellow, and offer protection from photooxidative stress by rendering highly reactive toxic oxygen species, which are produced by photochemical interactions, less chemically reactive. They also enable organisms to modulate the fluidity and permeability of their cell membranes, which would otherwise decrease at low temperatures, fatally impairing cells’ ability to function; and they’ve been reported to mitigate the harmful effects of dryness and nutrient depletion. Some normally heterotrophic organisms (i.e. those that harvest energy by consuming other organisms or their byproducts, rather than producing it through chemo- or photosynthesis) are even known to use carotenoids to capture solar energy in icy biomes when sources of food become scarce.


Because high levels of radiation can cause carotenoids to disintegrate, finding these pigments on the surfaces of moons and exoplanets with no atmospheres seems unlikely, but Ligia and the team have proposed searching for them in geyser jets, or in the near-subsurface of such extraterrestrial bodies. They’ve also proposed prioritizing celestial bodies with dry, icy surfaces, since carotenoids are more reflective under dry conditions, and thus more likely to be visible from outer space.


The fact that basic tools such as the database Ligia's working to build don’t yet exist underscores just how young the study of astrobiology is. “My field is very new,” she explained. “Most of my colleagues are astronomers, physicists, chemists even…for some reason, very few biologists. We’re trying to talk to each other using terms and concepts that are very distant from each other. We don’t yet share a technical language or a paradigm.”


For Ligia, these challenges aren’t just substantial in their own right, but also evocative of still more fundamental ones. When communicating with her colleagues, she must constantly code-switch, not only between the biological and astrophysical lexicons, but also between English and Portuguese. Her native language plays no role in the international scientific discourse, and everything she does professionally, she does in English. At the same time, the cloud of contradictory presuppositions that specialists from different disciplines bring to astrobiology echoes the persistent, grating dissonance between the formally accepted premise that women can make valuable contributions to the sciences, and the lingering sense that girls aren’t as good at math as boys.


Ligia’s greatest asset, when it comes to navigating these dynamics, is sheer chutzpah, which she refers to, tongue-in-cheek, as “my mediocre white male self-confidence.”


“I’m perfectly comfortable making my colleagues go slow and make things clear for me,” she said. “I mean, here I am, working in my second language and my second field…why should I be embarrassed?”


Though indisputably logical, Ligia’s gumption is all the more remarkable when one considers that it’s not only female or ESL scientists who feel the intellectual pressure. According to Ligia, many of her colleagues fear admitting what they do not know, especially after finishing their PhDs. “I’ve seen two guys talk for hours,” she said, “not understanding each other and not daring to admit that they don’t understand. Actually, it’s very common.”


Given the chilling effect that the specter of intellectual judgment can impose, any admission of ignorance takes enormous courage, but the immediate risks are offset, argues Ligia, by the mid-to-long-term gains. By forcing her colleagues to slow down and make things clear, she ensures her own continued intellectual growth, broadens her horizons, and deepens her understanding—and that, as she points out, is the whole point of scientific inquiry.


“I guess I’ve just always been like this,” she reflected. “I mean, I grew up wanting to go to space and study aliens, which in Portugal nobody was doing, and I was always like, ‘But what could possibly go wrong?’!”


To date, Ligia hasn’t gone to space herself, much to her mother’s relief, but she has deployed several payloads. These include a set of microalgae cultures, from which astronauts may someday grow food, and “Astrocups,” an experimental zero G menstrual cup designed to make long missions feasible for female astronauts. Both were side projects, undertaken in her spare time between collecting and processing samples in her PhD and now in her postdoc at Cornell. Both leverage her penchant for collaboration across institutions, nationalities, and disciplines. Finally, both hinge on her longstanding passion for breaking new ground.


Ligia’s dream for the future of astrobiology—a future that she’s actively shaping—is that it will bloom into a field where biologists have a seat at the table, and where researchers from different disciplines can communicate productively, united by a common set of concepts, terms, and paradigms. Only then, she believes, will researchers be able to recognize signs of extraterrestrial life—signs that they may still be missing even now, either because the right terrestrial datasets do not exist, or because biased assumptions about what life looks like and who ought to search for it have limited the search criteria and curtailed critical input and contributions.


“I would hate for us to be spending all this money on telescopes,” said Ligia, “and missing signs of life for silly reasons. We have to do the groundwork here and now if we ever want to make some sense of other worlds.”


Already, Ligia’s work has carried her far beyond the outer limits of the world that her mother knows. “It’s hard for me to tell her everything I do,” she said. “A lot of it, she doesn’t understand. Sometimes she’s sad because it’s taken me so far away, but at the same time, it’s what she’s always wanted for me—to succeed. She doesn’t know exactly what I’m up to, but she does know that she’s proud.”


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