Thomas Zurbuchen
Retired Director of the Directorate of Scientific Thesis
NASA
Nadia Drake
Science journalist
Sponsored by the IP Law Firm of MWZB, PC
Whether life exists beyond Earth is among the most exciting – and most difficult – mysteries that science can solve. For thousands of years, humans have wondered if we are alone in the universe, but those musings live almost exclusively in the realm of philosophy, not science. Sixty years ago, the first scientific search for extraterrestrial technologies was met with curiosity, and sometimes ridicule and derision. Only recently has the search for extraterrestrial intelligence (“SETI”) begun to gain traction and legitimacy among scientists.
The search for life beyond Earth is now a primary motivator and organizing principle of NASA’s science programs. The NASA Tiologyhe Act of 2017 mandated that the space agency make “the search for the origin, evolution, distribution, and future of life in the universe” one of its three primary exploration goals. (The other two goals are to protect and improve life on Earth and in space, and to explore the mysteries of the universe.) Finding life beyond Earth is one of NASA’s most challenging goals, and one of the most pressing.
This lecture will first frame the discussion of the search for extraterrestrial life in the context of the famous 1961 Drake Equation, a framework that relates physical, chemical, and biological processes to the development of detectable civilizations within our galaxy. And while the original form of the Drake Equation remains unchanged, we’ll highlight some changes in our understanding and definition of the equation’s variables—modifications that are a direct result of our growing understanding of the persistence of life in our homeworld.
Then, by adapting methodology from Neveu’s 2018 paper in Astrobiology, (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6211372/pdf/ast.2017.1773.pdf) the lecture will discuss three Ways the NASA science program focuses on identifying the signatures of life elsewhere in the universe.
First, by looking at exoplanets (worlds orbiting other stars). Estimates of the likely foothold of life on these worlds are based on statistical results from space missions and detailed spectroscopic observations of the planets’ atmospheres. This part of the lecture is timely and especially relevant because we are just getting the first spectra of exoplanets from the James Webb Space Telescope, and we are beginning to develop the technology that will enable the Habitable Worlds Explorer, NASA’s flagship astrophysics mission, specifically designed to study the atmosphere. to exoplanets and discover potential signatures of life in their spectra.
Second, coming closer to home, NASA’s science program focuses on the icy ocean worlds of our solar system. Whether it’s gaining knowledge about the building blocks of planets, or visiting exotic worlds like Titan and Europa — moons of Saturn and Jupiter, which may harbor life today — NASA seeks insights into processes that transcend the boundaries of our own world, and may have given rise to biology elsewhere. .
Third, the lecture will focus on Mars, our close companion to Earth. We have a long twenty-year history of sending rovers to the surface of Mars, and with the landers and orbiters to Mars, we have learned that although the planet is harsh and inhospitable by our standards today, it was once much warmer and wetter–a place with much greater promise for human forms. Life to evolve and thrive, either on its surface or beneath it, albeit billions of years ago. This search culminated in Mars Sample Return, humanity’s first round-trip to another planet, with the goal of delivering curated samples to the best laboratories on Earth.
Finally, the lecture will address NASA’s efforts to pinpoint the search for technical signatures—signs of intelligent alien civilizations. While historically most of these searches targeted radio emissions, today the scope of the search has expanded dramatically.