Whispers from Other Worlds NASA’s Search for Life in the Cosmos Thomas Zurbuchen & Nadia Drake

Thomas Zurbuchen
Retired Director, Science Mission Directorate
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 toughest — mysteries that science can solve. For millennia, humans have wondered whether we are alone in the cosmos, but those musings lived almost exclusively in the realm of philosophy, not science. Sixty years ago, the first scientific search for extraterrestrial technologies was met with curiosity, and at times cynicism and ridicule. Only recently has the search for extraterrestrial intelligence (“SETI”) begun to gain traction and legitimacy among scientists.

Looking for life beyond Earth is now a core motivator and organizing principle for NASA’s science programs. Tiologyhe NASA Authorization Act in 2017 mandated that the space agency make “the search for life’s origin, evolution, distribution, and future in the universe” one of three key exploration objectives. (The other two are to protect and Improve life on Earth and in space, and to explore the secrets of the universe). Finding life beyond Earth is one of NASA’s most challenging goals, and it is one of the most compelling.

This lecture will first frame the discussion of looking for extraterrestrial life in the context of the famed 1961 Drake equation, a framework that connects physical, chemical and biological processes with the development of detectable civilizations within our own galaxy. And, though the Drake equation’s original form has survived unchanged, we will highlight some changes in our understanding and definition of the equation’s variables – modifications that are a direct result of our growing understanding of life’s tenacity on our home world.

Then, adapting a methodology by 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 in which NASA’s Science program focuses on identifying signatures of life elsewhere in the universe.

First, by looking at exoplanets (worlds orbiting other stars). Estimates of life’s possible footholds on these worlds are informed by statistical results from space-based missions and detailed spectroscopic observations of planetary atmospheres. This part of the lecture is particularly timely and relevant as we are just getting the first exoplanet spectra from the James Webb Space Telescope, and starting technology development that will enable the Habitable Worlds Explorer, NASA’s next astrophysics flagship mission, designed specifically to study exoplanet atmospheres and to detect possible signatures of life in their spectra.

Second, moving closer to home, NASA’s science program is focused on icy ocean worlds in our own solar system. Whether it is about gaining knowledge of planetary building blocks, or visiting bizarre worlds such as Titan and Europa — moons of Saturn and Jupiter, which might harbor life today — NASA is seeking to gain insights into processes that transcend the boundaries of our own world, and might have given rise to biology elsewhere.

Third, the lecture will focus on Mars, our near-Earth companion. We have a twenty-year-long history of sending rovers to the Martian surface, and together with landers and orbiters to Mars, we have learned that although the planet is harsh and inhospitable by our standards today, it was once warmer and wetter — a place with considerably more promise for lifeforms to evolve and thrive, either on or below its surface, albeit billions of years ago. This research is culminating in the Mars Sample Return, humankind’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 effort to define the search for techno-signatures — signs of intelligent alien civilizations. While most of these searches have historically targeted radio emissions, the search today has broadened considerably.