The association has enjoyed presenting many notable individuals as guest lecturers during our general meetings. Recordings of many of these talks can be found on our youtube channel guest speaker playlist. Recent talks include:
Saturday Oct 22nd, 2026 – Small Town Universe Film Screening and Chat with the Film-maker
Katie Dellamaggiore, Director and Producer at Rescued Media
Small Town Universe explores life in Green Bank, West Virginia – a remote community located inside the National Radio Quiet Zone. Here, the use of wireless technologies such as cell phones and Wi-Fi is heavily restricted to prevent interference with the nearby Green Bank Telescope, the world’s largest fully-steerable radio telescope.
The film follows four unique residents whose lives are intertwined with the town and its namesake telescope: a young woman dreaming of a career in astrophysics, a retired engineer reflecting on his legacy, a longtime local rooted in Green Bank’s history, and a newcomer embracing life off-the-grid.
As federal funding hangs in the balance, their futures are inextricably tied to the survival of this scientific marvel and the Quiet Zone that makes it all possible.
Saturday July 25th, 2026 – Hunt for Gravitational Waves: A story spanning the frequencies of space-time
Santanu Parmar, Cornell University
Gravitational Waves are the ripples in the fabric of space-time created by some of the most violent dances in the universe between heavy, dense and extreme objects called compact binaries. Compact objects include star remnants such as white dwarfs, neutron stars and black holes. When two of such compact objects get trapped into each other they spiral with increasing speed towards their shared center and eventually collide, forming strong ripples in space-time that we detect from earth.
There have been many efforts in GW detection since the 1900s, the most recent and famous of which is LIGO. But there are also upcoming missions such as the LISA mission spearheaded by the ESA and the NANOGrav collaboration’s work on pulsar timing arrays. In this talk, we will see an overview of the targets, data analysis pipelines and upcoming research in each of these three quests. (recording)
Saturday June 27th, 2026 – Lick Observatory: A Journey Through the Eras
Eric Bricmont, Lick Observatory
Join me as we take a brief look at the history of the world’s first permanent mountain top observatory. We will briefly explore the life of Californians first millionaire, James Lick and the accomplishments of the extraordinary gift he left behind. (recording)
Saturday May 30th, 2026 – High Altitudes for High Energies: Chasing Solar Flares by Balloon
Meredith Wieber, UC Berkeley
Solar flares drive space weather which can affect satellites, astronauts, and life on Earth. Having a better understanding of what drives solar flares can lead to better space weather prediction. In this talk, I will discuss the GRIPS (Gamma-Ray Imager/Polarimeter for Solar flares) high altitude balloon mission and its applications for studying particle acceleration in flares. Join me to explore the world of low-cost access to space, solar flare science, and the implications of space weather! (recording)
Saturday May 2nd, 2026 – Celestial Tales: The Winter Giants
Rashi Girdhar, SJAA
This was adapted from our Astro 101 series for our public speaker program. During this hour, we went through the winter chapter of a four-part expedition across the seasons. If you enjoy this program please check out the rest of Astro 101 here https://www.sjaa.net/programs/beginners-astronomy/
We shared share stories told about the stars in the night sky, journeying from ancestral tales to the rituals that shaped civilization. We walked in the footsteps of the pioneers, legends, rebels, and geniuses who paved the way for modern astronomy: Aristarchus who’s radical thinking got ahead of accepted science by 2000 years, Hypatia the master of the ‘cosmic clock’, and Annie Cannon who decoded the colors of the stars. These stories illuminate the awe and wonder that eventually converged into modern science.
Saturday Mar 7th, 2026 — Black Holes: Discovering the Invisible
Natasha Abrams, PhD student, UC Berkeley
Black holes are some of the most extreme objects in the universe. They push the boundaries of our knowledge and hold many unsolved mysteries. Come learn about black holes from “small” to enormous. We will discuss the techniques we use to discover and characterize them and explore the frontiers of astrophysics! (recording)
Saturday Jan 3rd, 2026 — The (Life and) Death of Stars: Where the Elements Around Us Form
Natalie LeBaron, PhD student, UC Berkeley
From the oxygen we breathe to the gold in our jewelry and the calcium in our bones, the majority of periodic table elements that make up our world are forged by stars. This talk explores how the universe transforms simple hydrogen into the rich diversity of atoms that build planets, life, and everything we see around us. Beginning their lives in vast clouds of gas and ending in massive explosions, we will discover how each star in the night sky creates and scatters ingredients for new worlds throughout their evolution. By tracing this stellar alchemy, we uncover how true it is to say that we are all just stardust. (recording)
Saturday Dec 6th, 2025 — Building a DIY optical path towards the universe
Dr. Zheyuan Zhu, SJAA Member
The field of optics was born from the curiosity of early astronomers, whose pioneering work laid the foundation for theories ranging from ray optics to electromagnetic field theory. These advances fulfilled humanity’s enduring quest for sharper vision and greater fidelity across microscopic and macroscopic scales—an endeavor we now recognize as imaging. In this talk, we will introduce some history and fundamentals in optical imaging, specifically the quantitative metrics to describe the quality of an imaging system and its sensitivity to optical and mechanical misalignment. Leveraging my training in imaging system, I will share the motivations and design considerations that went into my DIY astronomy setups from the early prototypes to the latest Astronomical Imaging & Metrology System (AIMS), along with lessons learned in each iteration. These hands-on experiences ultimately led to a service mission at UCF’s Robinson observatory to restore its “eyesight” and paved the way for its on-going research in astro-photonics. (recording)
Saturday Nov 1st, 2025 — Emerging pictures of other worlds
Dr. Bruce Macintosh, UC Observatories
In the past three decades, more than 6000 planets have been discovered orbiting other stars beyond our own Solar System. This has sparked a revolution in astronomy as we realize our Solar System is not alone. However, we still don’t know if our Solar System is rare or unique – the powerful techniques that detect extrasolar planets have discovered systems very different than our own. In recent years, advances in technology have allowed a handful of giant planets to be imaged directly.
I will discuss the first-ever images of other solar systems – and the technology that has allowed us to discover them, such as the Gemini Planet Imager – as well as the future planet-hunting space telescopes. The ultimate goal is detection of a second “pale blue dot” – an Earth twin where we could even see the biosignatures of extrasolar life. Such a discovery will truly complete the evolution of our view of the Universe. (recording)
Saturday Oct 4th, 2025 — Show and Tell
Various SJAA Members
We took a break from longer talks and did a round of quick “show and tell” presentations by various members. (recording)
Saturday September 6th, 2025 — The challenges of crewed long-duration exploration missions to the Moon and Mars
Dr. Katya Sofia Arquilla, University of Colorado, Boulder
Human spaceflight has enabled many scientific discoveries that would not have been possible without the presence of skilled, adaptable, and creative human crews in space, but sending humans into space challenges their physiology, psychology, and general performance. Long-duration exploration missions present challenges more intense than those encountered in low-Earth orbit, with limited communications, limited access to resupply, challenging transitions between space exploration environments, and smaller spacecraft than what most current astronauts have experienced on the International Space Station. The unique challenges of missions to the Moon and Mars require creative solutions, including methods of monitoring health, strategies for managing the effects of communication delays, and plans for teams of humans and autonomous robotic systems working together to explore the rich scientific data available on these extraterrestrial surfaces. (recording)
Saturday August 9th, 2025 — Deep Space Optical Navigation
Declan Mages, Jet Propulsion Laboratory
A critical aspect of all interplanetary missions is answering the following questions: where is the spacecraft now, where has it been, where is it going, and what needs to be done to get it where it needs to go. This is the job of the navigator, a role with origins at JPL alongside the Deep Space Network in early 60s. While most interplanetary missions can be flown using just radiometric tracking data from the Deep Space Network, some missions require the addition of optical navigation data. With heavy overlap with the field of astronomy, optical navigation is the practice of using an imager onboard the spacecraft to image and observe a target body. With this data, navigators can pinpoint the orbits of asteroids for precise flyby or determine a spacecraft’s precise orbit based on surface features and altogether enable ambitious investigation of unknown worlds.
Saturday Jul 12th, 2025 — New Technology for Exploring Other Worlds
Dr. Phil Hinz, Director Laboratory for Adaptive Optics, UCSC
Planets around other stars are not just the domain of science fiction anymore. Over the past 30 years astronomers have gone from no knowledge of planets around other stars to being able to say how common or rare they are (spoiler: they’re common). Are any of these planets habitable? Do any of them have life? To learn this, we need to develop improved telescopes and instrumentation. Two key tools for this are adaptive optics (AO) and the development of large segmented mirror telescopes(LSMT). AO corrects for the blurring effects of our atmosphere, allowing us to effectively separate the planet from the overwhelmingly brighter light of its parent star. I will discuss the technology development being carried out at the UC Observatories to integrate AO and LSMT technology. The resulting large aperture adaptive telescope concept can provide the light gathering capability and precision imaging needed to scour our neighboring stars for Earth-twin planets.
Saturday May 10th, 2025 — Fast Radio Bursts: An Enduring Cosmic Mystery
Dr. Bryan Gaensler, University of California, Santa Cruz
In August of 2001, an extremely bright, brief, extraterrestrial radio signal washed over the Earth. This flash of radiation lasted just a few milliseconds, originated from around four billion light years away, and contained more energy in a fraction of a second than the Sun gives off in an entire year. Almost 25 years later, astronomers have now found thousands more of these “fast radio bursts”, but incredibly, we still have no idea what they are. Professor Bryan Gaensler will explain how fast radio bursts were discovered, why they’re so enigmatic, and how they could be key to understanding some of the fundamental properties of the Universe. (recording)
Saturday April 5th, 2025 — Chasing Asteroid Occultations for Adventure and Science
Dr. Richard Nolthenius, Instructor, Cabrillo College
Asteroids are a rapidly emerging field of importance in Astronomy. With the release now of the GAIA Mission high precision astrometry of both stars and asteroids, it is now possible for citizen astronomers to get data that permits more accurate astrometry than the most powerful telescopes. Asteroids’ slow orbital motion, and our ability to GPS time stamp high speed video frames, we can pin down not only their centroid position, but the detailed shape and presence of possible moons of these objects. Kepler’s 3rd Law then permits measuring directly their bulk density, putting tight constraints on their composition. What are they made of? Surface reflection only gives clues of surface composition, not their bulk characteristics. What is their formation history? Collisional? Slow accretion? Astronomer Richard Nolthenius is one of the most prolific and long time gatherers of the raw data for these questions, and with equipment easily accessible to dedicated amateur astronomers, thanks to the volunteer efforts of members of the International Occultation Timing Association. He will share his experiences, the gear needed, and highlights of the asteroid adventures he’s organized for his growing team of fellow ‘roid chasers in Santa Cruz. (recording)
Saturday March 15th, 2025 – Some Astronomy in Classical Hohokam and Mimbres Locations
Robert Garfinkle FRAS (Fellow Royal Astronomical Society)
During the classical period of the Hohokam and Mimbres tribes of the Native Americans of Arizona and New Mexico, the Hohokam built the Casa Grande structure (now ruins in Coolidge, AZ) and used it for astronomical observations. In the year 1054 CE, the Mimbres observed a bright new star visible for 23 days in the daytime sky that actually was the Super Nova, now known as the Crab Nebula (M1). Robert’s PowerPoint presentation will cover these hundreds of year-old events. (recording)
Saturday, Jan 11th, 2025 – Unravelling the mysteries of globular clusters, dwarf galaxies, and dark matter
Dr. Aaron Romanowsky, Researcher UC Santa Cruz
The visible grandeur of the Universe, with galaxies clustered into vast structures, is understood to originate in smaller components that are difficult or impossible to see. These components include dwarf galaxies, star clusters, and dark matter particles — all of them presenting major mysteries about their nature and origins. I will discuss ongoing research in these areas, primarily focused on nearby galaxies using new observatories and tools both from the ground and from space, and including the contributions of students to making significant discoveries.
Saturday, Dec 14th, 2024 – The origin of the Universe & evolution of large scale structure and how it affects your observing
Jorden Woods, Caltech-trained Astronomer working in Venture Capital
This talk is geared toward astronomy enthusiasts and amateur astronomers. I’ll provide an overview of the origin of the Universe, early galaxy & stellar formation, and the evolution of large scale structure. Also, I’ll discuss the latest research, including exciting insights from the James Webb Space Telescope (JWST), and some of the ‘tensions’ that are animating and roiling the research community. We’ll then delve into how the formation of the universe affects what we observe astronomically and how these insights can make your observing more enjoyable.
Saturday Oct 19th, 2024 – Space Archeology : Studying Early Universe Using Remote Radio Telescopes
Akshatha Vydula, Ph.D.(Astrophysics) Candidate, School of Earth and Space Exploration, Arizona State University
In the evolution of the Universe, there remains a gap in understanding the formation of first stars and galaxies, ~300,000 years after the Big Bang. These early stars brought with them the first light in the Universe, thus leading to ‘Cosmic Dawn’. Although this is an event of the past, the spin-flip transition of an electron in the neutral hydrogen (called the 21 cm signal) remains a tracer of the early Universe. This talk is about how we use this tracer in radio astronomy to bridge the gap between formation and the present day Universe.
Information about older presentations:
10/28/2023 – Exploring the Sky Through Astro Imaging, Glenn Newell , (recording)
4/8/2023 – Science and Technology Innovation at Lick Observatory, Dr. Elenor Gates, (recording)
11/7/2020 – You can almost touch the stars, Tom Field (recording)
10/3/2020 – A Cosmic Perspective: Searching for Aliens, Finding Ourselves, Dr. Jill Tarter (recording)
7/11/2020 – Launching to Mars in 2020, a Primer on the NASA Perseverance Rover’s Mission to Return Samples and Search for Life on Mars. J.R. Skok, PhD, Planetary Scientist, SETI Institute (recording)
5/9/2020 – SJAA Online Astronomy Talk – A Low Cost Radio Telescope Project, Karen Lei, Anna Dymchenko, Connor Galvin, Saratoga HS Astro (recording, posted 7/7/2020)
6/6/2020 – SJAA Online Astronomy Talk – Fantasy Flights to the Moon, Robert A. Garfinkle, author of Luna Cognita, A Comprehensive Observer’s Handbook of the Known Moon. (recording. posted 7/7/2020)
3/15/2016 – SIG: Untwinkling the Stars, Adaptive Optics at Lick Observatory, Dr. Elenor Gates, (recording posted 7/7/2020)
