In-Person
Shining a Light on Dark Matter
Registration Opens March 31, 2026 | Dr. Andrew Robertson will explain how astronomers came to believe that dark matter exists, and how some gargantuan collisions of galaxy clusters provide some of the strongest supporting evidence for its existence.
Monday, March 30, 2026
7:00 p.m. PT
7:00 p.m. PT
Andrew Robertson | Postdoctoral Fellow, Carnegie Science Observatories
Carnegie Science Observatories postdoc Andrew Robertson focuses on one of the key mysteries in contemporary astronomy: the nature of dark matter. We know that this mysterious form of matter makes up about 85 percent of the mass in the universe, but astronomers still don’t know exactly what it is. Drawing on his experience as a former postdoc at NASA’s Jet Propulsion Laboratory, Robertson will explain how astronomers came to believe that dark matter exists, and how some gargantuan collisions of galaxy clusters—particularly the famous "Bullet Cluster"—provide some of the strongest supporting evidence for its existence. He’ll demonstrate how these extreme cosmic collisions can be used to probe the fundamental properties of dark matter itself.
Image credit: The Bullet Cluster X-ray: NASA/CXC/M. Markevitch et al.; Optical: NASA/STScI; Magellan/U. Arizona/D. Clowe et al.; Lensing Map: NASA/STScI; ESO WFI; Magellan/U. Arizona/D. Clowe et al.
