Presenter is the Project Scientist, Dr. Robert Pappalardo (JPL)
May 22, 2024

Jupiter's moon Europa may be a habitable world, containing the “ingredients” necessary for life within its ocean. Data from NASA’s earlier Galileo mission suggest that a global, salty ocean exists beneath the icy surface. Tides have broken that floating ice shell to create impressive ridges, bands, and chaotic terrains. The Europa Clipper mission will explore Europa with a suite of instruments, through multiple close flybys from Jupiter orbit, examining the moon’s ice shell, ocean, and geology.  And it will search for current activity –including plumes that emerge from surface cracks. Dr. Pappalardo, the mission's Project Scientist, summarizes our understanding of Europa and the and status and promise of the Europa Clipper.

Apr. 17, 2024
In this talk, physicist and popular author Paul Halpern (St. Joseph's College) examines the history of the concept of a multiverse in science, and discusses the ideas by Einstein and other noted physicists that have led scientist today to take the notion of multiple universes seriously.  He also contrasts the scientific view of a multiverse to the picture we get in popular culture (think Marvel movies) and notes how significantly the two differ.  Dr. Halpern is the author of a new popular-level book also called "The Allure of the Multiverse" and many other nontechnical science books.

With Dr. Leonard Susskind (Stanford University)
Black holes, the collapsed remnants of the largest stars, provide a remarkable laboratory where the frontier concepts of our understanding of nature are tested at their extreme limits. For more than two decades, Professor Susskind and a Dutch colleague had a running battle with Stephen Hawking about the implications of black hole theory for our understanding of reality — a battle that he has described in his well-reviewed book The Black Hole Wars. In this talk Dr. Susskind tells the story of these wars and explains the ideas that underlie the conflict. What's at stake is nothing less than our understanding of space, time, matter and information!

Recorded: October 1, 2008
        Although this was taped some years ago, this was the most popular talk in the 24-year history of our series.  So we wanted to make it available as a podcast, so new audiences could also hear it.

A Non-technical Talk by Dr. Jessica Lu (University of California, Berkeley) on March 13, 2024

The population of black holes, objects left over from dead stars,  is almost entirely unexplored. Only about two dozen black holes are confidently known in our Galaxy. As a result, some of the most basic properties of black holes remain unknown, including the true number of black holes in the Galaxy, their masses and sizes, and how the black holes were formed.  Dr. Lu discusses how she and other astronomers are using "gravitational lensing" -- something predicted by Einstein’s work -- to open a new window onto black holes, and how the first free-floating black holes are now being discovered.  She explains, in everyday language, why astronomers expect that the number of known black holes will increase by a factor of 100 over the next decade.

Speaker: Dr. Brian Lantz (Stanford University)
Feb. 7, 2024
Measuring gravitational waves is a revolutionary new way to do astronomy.  They were predicted by Einstein, but it was not until 2015, that LIGO (the Laser Interferometer Gravitational-wave Observatory) first detected one of these waves. They were tiny ripples in space itself, generated by the collision of two black holes. Since then, LIGO and its international partners have measured nearly 100 signals. Dr. Lantz explains what we can learn from these bursts of energy and just how it is possible to measure a wave which stretches our detector 1000 times less than the diameter of a proton. And he discusses what's coming next in our search for these tell-tale ripples in space? 
Dr. Lantz is the scientific leader for the Advanced LIGO seismic isolation system,

Dr. Laura Schaefer (Stanford University):
Water is everywhere. Its atoms, hydrogen and oxygen, are the first and fifth most abundant elements in the universe. Water is found in abundance in many environments; it finds its way into planets of all shapes and sizes, where it modifies the properties of everything it touches. Water is crucial to life, both as a habitat and as a solvent. But it also has many other roles in the evolution of habitable and uninhabitable environments on a planetary scale. In this talk, Dr. Schaefer discusses the ways in which Earth acquired its water, how water modifies the evolution and habitability of the Earth, and how the habitability of rocky planets orbiting other stars may be different.  

Laura Schaefer is an Assistant Professor of Earth and Planetary Sciences at Stanford University. She is a planetary scientist who focuses on how gases and rocks react with each other to form the atmospheres of rocky planets, both inside and outside the Solar System.  

The talk was given November 15, 2023.

A Talk by Dr. Robert Jedicke (U of Hawaii)
Oct. 11, 2023

Near-Earth objects present both an existential threat to human civilization and an extraordinary opportunity to help our exploration and expansion across the solar system. Dr. Jedicke explains that the risk of a sudden, civilization-altering collision with an asteroid or comet has markedly diminished in recent decades -- due to diligent astronomical surveys -- but a significant level of danger persists. At the same time, remarkable strides have been made in advancing technologies that pave the way for a new vision of space exploration – one that involves missions and outposts within the inner solar system fueled by resources extracted from near-Earth asteroids. These objects contain exploitable extraterrestrial resources delivered free to the inner solar system, and they have been naturally preprocessed into objects the ideal size for industrial operations. 

Robert Jedicke obtained his Ph.D. in experimental particle physics from the University of Toronto and held post-doctoral positions at the Fermi National Accelerator Laboratory and at the University of Arizona’s Lunar & Planetary Laboratory. At the University of Hawai`i’s Institute for Astronomy for the last 20 years, he managed the development of the Moving Object Processing System for the Pan-STARRS telescope on Maui.

June 2012
Frank Drake (1930-2022) was known as the "father of SETI science" -- he was the scientist who conducted the first radio survey for signals from extraterrestrial civilizations, and came up with the formula for estimating the likelihood of such civilizations, now called the Drake Equation. 

In June 2012, the SETI Institute sponsored a three-day public event called SETICon. One highlight of the program was an interview with Drake (who served as the founding President of the Institute board. )  It was conducted by SETI Institute board member and veteran astronomy educator Andrew Fraknoi.  The discussion ranged widely over Dr. Drake's career and current thinking.  It included reminiscences of Project OZMA, that first experiment searching for signals from civilizations among the stars, and his current view of the Drake Equation.  He also reflects on a number of modern developments, including the discovery of numerous planets orbiting other stars and new ways of searching for extra-terrestrial civilizations.

During the Summer, when the Silicon Valley Astronomy Lectures take a vacation, we thought you might enjoy this special podcast for its historical value, now that Frank Drake has passed away.

with Dr. Eugene Chiang (University of California, Berkeley)
June 21, 2023
We now know that our solar system is but one of countless others. Where did all these planets come from? What are their fates, and ours? Dr. Chiang describes the life cycle of planets, how they are born and die, and how they are born again. The story combines the latest observations from a wide range of telescope with our evolving theoretical understanding of the role planets play in the development of the cosmos.

North America will be treated to two eclipses of the Sun in the 2023-24 school year: an annular eclipse on Oct. 14, 2023 and a total eclipse on Apr. 8, 2024.  Some 500 million people will be in a position to see at least a partial eclipse on each date. Astronomer Andrew Fraknoi (Fromm Institute, University of San Francisco) discusses the cause of eclipses (and why Earth's eclipses are unique), the circumstances of each coming eclipse and where each will be visible, plus how to view eclipses safely.  He shows maps of the eclipse paths and provides URLs to where you can get free information materials to help you enjoy eclipses without hurting your eyes, wherever you are.   (For more about Andrew Fraknoi and his educational outreach work, see: http://fraknoi.com )