| Abstract: Ultralight dark matter induces time-varying perturbations in the spacetime metric, offering a pathway for its gravitational detection. In this talk, I introduce a novel approach using astrometry to detect such dark matter. I first discuss the calculation of the spacetime metric under the influence of scalar dark matter and then examine how these perturbations impact the apparent motion of astrophysical bodies. This analysis is applied to the angular position measurements of quasars, which, due to their vast distances from Earth, provide a unique opportunity to detect dark matter with masses as low as 10^{-33} eV. Finally, I discuss the prospects of very long baseline interferometry and optical astrometric survey measurements for detecting ultralight relics. Link to the Event Video |