Paul Hertz Director of Astrophysics: NASA (since 2012) Chief Scientist: NASA’s Science Mission Directorate (previously) Ph D.: Astronomy: Harvard University (1983) Author: Over 100 refereed science papers (involving every electromagnetic band from radio to gamma-ray)

How will humanity first discover ET Life? Best guess: Biosignatures (distant exoplanets) Life will be found first on an exoplanet, not in the Solar System About Life Not a rare process Arose rapidly on Earth after conditions were right Should arise in some reasonable fraction of other places, when conditions are right

Where can life be found? Solar System   Only 2 or 3 places where conditions might have been appropriate for life to arise in our Solar System the last 4 billion years Unless life is likely in appropriate conditions, Earth is the only place in our Solar System where life developed Distant Exoplanets 10-20% of Sun-like stars have Earth-like planets in the habitable zone Around a billion potential sites for life to arise on an exoplanet likely exist in our galaxy alone NASA is involved in the development of technologies, mission concepts, and observatories to find life on these exoplanets

Return to 100th Anniversary Page