Free and open to the public. Arrive a few minutes early for snacks and socializing :-)

We welcome MSc Ried Guachalla, of the Kavli Institute of Particle Astronomy at Stanford.

The universe is glowing with ancient light left over from the Big Bang. When that light passes through galaxies, their gas leaves faint “silhouettes” we can measure. With modern telescopes and massive sky surveys, we can use these shadows to reveal hidden matter. In this talk, I’ll show how we use ancient light to map the invisible surroundings of galaxies and what it’s teaching us about how galaxies grow and change.

https://www.sfaa-astronomy.org/public-events/lectures/lectures_2026/feb18_2026