Join us for our April lecture in our 2025-26 AAA Lecture Series! This month’s lecture features Andrew Fraknoi from the Univ. of San Francisco & San Francisco State Univ and is our annual John Marshall Memorial Lecture.

The Fermi Paradox: If the Universe is Teeming with Planets and Life, Where are All the Aliens?

An Illustrated, Nontechnical Talk by Astronomer Andrew Fraknoi

Registration: https://us02web.zoom.us/webinar/register/WN_nTBfvdsbQouClWAY6PrKGw

Astronomers have now discovered thousands of planets orbiting other stars, some of them located in zones where life might comfortably exist. If, as scientists now conclude, there may be billions of Earth-like planets out there, why have we not been visited by alien tourists? This is what the great physicist Enrico Fermi asked in the 1950s. Knowing more about the vast scales of space and time, we can now answer Fermi in a variety of imaginative ways and explain why evidence of intelligent life out there may be harder to find that we thought.

Andrew Fraknoi is a retired astronomer and college professor.  He is the lead author of the free, online book “Astronomy,” published by the nonprofit OpenStax project, which has become the most frequently-used introductory astronomy textbook in North America.  In addition, he has been author or co-author on two children’s books and several activity manuals for teachers.  Recently he has been writing science fiction based on good astronomy, and has had eleven stories published so far.  He served as Executive Director of the Astronomical Society of the Pacific for 14 years and is on the Board of Directors of the nonprofit SETI Institute, a scientific and educational organization, dedicated to the search for life in the universe. He was chosen as the California Professor of the Year in 2007. The International Astronomical Union has named Asteroid 4859 Asteroid Fraknoi, in recognition of his contributions to the public understanding of science.  For more on his educational work and science fiction, please see: https://fraknoi.co