Have you ever seen the movies E.T., Men in Black, or Close Encounters of the Third Kind? If not, close this page and go watch them! Because besides being cult classics, these films are directly related to this month’s theme: astrobiology!
What is Astrobiology?
Just as designing a car requires a bit of mechanics, marketing, design, electronics, and many other fields, astrobiology (also called exobiology) is an interdisciplinary scientific discipline that combines astronomy, astrophysics, biology, chemistry, and geology. But unlike automotive engineering, astrobiology doesn’t produce anything. No. It explores the Universe in search of other forms of life! Isn’t that cool?
Its goal is to understand the conditions necessary for the “emergence and persistence of life, not only on Earth but also elsewhere in the universe. To do this, we must understand what life is (which is not obvious to begin with)? Then, to what extent can it develop (to narrow down the search field… We are talking about the UNIVERSE after all)? And then, we need to study possible locations, produce calculations, models, … Because we can’t go to this or that planet ourselves to take a lo” ok!
Astrobiologists therefore focus on three main areas of research:
1 – The Study of the Origins of Life
A major focus is understanding the conditions that allowed life to appear on Earth. Researchers attempt to recreate the primitive conditions of Earth to test theories about the emergence of life, studying phenomena such as the formation of the first complex organic molecules and the emergence of biochemistry.
The question of defining what life is in itself is also debated: we don’t know how to precisely define what is alive and what is not. A surprising observation, you might say.
Because while it’s simple to demonstrate through A+B that your pet is indeed a living being, we quickly realize that it’s less so for other beings that nevertheless live with us, even inside us, every day: viruses. This is a topic to follow in the coming years!
2 – The Search for Extraterrestrial Life:
One of the main challenges of astrobiology is detecting life elsewhere in the universe. Missions to planets and moons like Mars, Europa (a moon of Jupiter), or Enceladus (a moon of Saturn) aim to identify traces of life, current or past, in extraterrestrial environments.
3 – The Search for Life in Extreme Environments:
The “study of extremophile organisms, capable of living in extreme conditions on Earth (for example in hot springs, deep sea floors, or the most arid deserts), allows astrobiologists to better understand how life could exist in environments very different from those we know, such as on Mars or the icy moons of the solar system. This would allow us to consider new models of organisms, to expand our research, and perhaps to better understand how life might have appeared on Earth 4 billion years ag” o…
The implications of astrobiology are multiple and far-reaching. The discovery of extraterrestrial life would revolutionize our understanding of humanity’s place in the universe. It could also answer profound questions about the rarity or universality of life, challenging our philosophical, religious, and existential beliefs. From a scientific standpoint, astrobiological research raises fundamental questions about what constitutes a “life form” and the minimal conditions necessary for a planet to harbor a biosphere.
Finally, astrobiology is a highly technological field. Detecting biomarkers in exoplanetary atmospheres, searching for fossil traces on Mars, or building robots capable of simulating extraterrestrial conditions require constant technical innovations and advances in chemical and physical analyses.
What About Women in All This?
Dr. Sara Seager
This Canadian astrobiologist is a leading figure in the field of astrobiology. A professor at the Massachusetts Institute of Technology (MIT), she is best known for her research on detecting extraterrestrial life through the study of exoplanets and their atmospheres. She is “one of the pioneers in researching potential biosignatures on” other worlds.
“One of Seager’s most important works has been developing methods to analyze the atmospheres of” exoplanets in search of signs of life. In 2013, she proposed a model for detecting biosignatures in exoplanet atmospheres, such as traces of methane, oxygen, or carbon dioxide, molecules that are, on Earth, associated with biological processes. This research is crucial for current and future “observation missions, such as the James Webb Space Telescope (JWST), which will have the ability to” analyze the atmospheres of distant planets and search for signs of life.
Seager has also designed instruments and projects to enable direct observation of exoplanets, such as the Starshade telescope. This project aims to reduce the glare from stars to more easily observe the planets orbiting them. This technology will eventually allow us to determine if exoplanets have habitable atmospheres and if they could harbor life.
Finally, one of Seager’s most notable contributions has been her research on the oxygen biosignature. By studying the atmospheric and chemical conditions that could allow a planet to have oxygen, she established rigorous criteria for identifying exoplanets that would be likely to support life, even if that life was not immediately apparent.
Dr. Nathalie Cabrol
Nathalie Cabrol, a French-born astrobiologist and geobiologist, is a key figure in the field of searching for life in extreme environments. A professor at the SETI Institute, Cabrol is particularly known for her work on Martian analogues on Earth, environments where life could potentially exist on other planets, such as Mars.
One of Cabrol’s main contributions has been her research in extreme areas of Earth, such as the Atacama Desert in Chile, one of the driest places in the world. In these environments, the conditions of temperature, humidity, and radiation are close to those that exist on Mars.
By studying these environments, Cabrol has been able to demonstrate that life forms can survive, and even thrive, in extremely hostile conditions. This research has helped to understand how life could survive on Mars, particularly in underground cavities or at the poles, where liquid water could exist in the form of ice or mist.
Cabrol has also led several “exploration missions on subglacial lakes in Antarctica, environments analogous to the underground water reservoirs that could be discovered on Mars. Her research has been crucial in understanding how life could” develop in very cold and isolated conditions. She has participated in establishing protocols for searching for biomarkers and traces of life in glacial and underground environments, techniques she has used in Martian missions.
Another key aspect of her work is collaboration with multidisciplinary teams, combining geologists, biologists, and engineers, to design instruments and methodologies for exploring rocky planets, particularly Mars. Cabrol has contributed to the planning of missions to study Mars’ geology and its potential capabilities to support life, notably by analyzing the formation of minerals and soils that could be linked to past or present biological processes.
Today, “Nathalie Cabrol’s work continues to play a crucial role in astrobiological research. It notably allows for a better understanding of the conditions necessary for the” emergence of life and how we can detect these signatures in the universe.
Written by Inès and edited by Mazzarine
Sources
Seager, S. et al. (2013). A search for life on exoplanets. Science, 340(6133), 577-584. https://doi.org/10.1126/science.1236213
Seager, S. (2013). Exoplanet Atmospheres: Theoretical Concepts and Observational Challenges. University of Arizona Press.
Cabrol, N. A., et al. (2007). Life in Extreme Environments: Insights for the Search for Life on Mars. Astrobiology, 7(4), 617-634. https://doi.org/10.1089/ast.2007.0214
Cabrol, N. A., & Grin, E. (2010). Lakes as Mars Analogs. Earth and Planetary Science Letters, 294(3-4), 276-285. https://doi.org/10.1016/j.epsl.2009.05.013
NASA Astrobiology Institute. (2022). Research and Findings. https://astrobiology.nasa.gov
https://exobiologie.fr/lexobiologie-2/naissance-dune-discipline-lexobiologie/
