For most of human history, Earth stood alone as the only known habitable and inhabited world. Now, humanity is at the cusp of being able to detect extra-terrestrial life beyond Earth. The discovery of more than 6,000 exoplanets—planets orbiting stars beyond our Sun—has revealed a galaxy filled with planetary systems far more diverse than previously imagined. These discoveries raise a new generation of questions: Which of these worlds could support life? How common might life be in the Galaxy? And could advanced civilizations leave detectable imprints on their planetary environments?
In this talk, I will highlight key milestones in exoplanet discovery, with a focus on potentially habitable worlds. I will discuss current efforts to identify biosignatures—atmospheric indicators of biological activity—and technosignatures—observable consequences of technology—and conclude with discussing the current and planned missions to find extraterrestrial biological and technological life, and prospects of identifying such life through remote observations.