Physics Colloquium

From Lab to Cosmos: Three Frontiers in the Search for Signs of Life Beyond Earth

The search for life beyond Earth is often framed around water as the essential solvent, yet many exoplanets are too warm for surface liquid water. Our recent experiments show that some key biomolecules—including amino acids, peptides, and a genetic-like polymer—can remain stable in concentrated sulfuric acid, the dominant liquid in Venus' temperate clouds. Under the same conditions, lipids can even self-assemble into vesicles. This surprising chemistry reopens the question of whether Venus might be habitable. While building instrumentation and conducting laboratory studies for Venus' clouds, we inadvertently "rediscovered" ionic liquids—exotic, polar, non-volatile solvents—and showed for the first time that hydrogen sulfate ionic liquids can form naturally from planetary materials. Ionic liquids remain stable under extreme conditions where water cannot exist. Together, these findings expand the concept of habitability beyond Earth-like environments, pointing to new mission pathways for detecting signs of life beyond Earth. By considering alternative solvents, we can begin to chart new frontiers that integrate quantum chemistry, biomolecular chemistry, planetary physics, and space exploration—potentially transforming our understanding of life's origins and its possibilities across the cosmos.

Join via Zoom:
https://caltech.zoom.us/j/84497014003
Meeting ID: 844 9701 4003

The colloquium is held in Feynman Lecture Hall, 201 E. Bridge.