Novel constraints on fifth forces and ultralight dark sector with asteroidal data

We study for the first time the possibility of probing long-range fifth forces utilizing asteroid astrometric data, via the fifth force-induced orbital precession. We examine nine Near-Earth Object (NEO) asteroids whose orbital trajectories are accurately determined via optical and radar astrometry. Focusing on a Yukawa-type potential mediated by a new gauge field (dark photon) or a baryon-coupled scalar, we estimate the sensitivity reach for the fifth force coupling strength and mediator mass in the mass range $m \simeq (10^{-21}-10^{-15})\,{\rm eV}$, near the ``fuzzy'' dark matter region. Our estimated sensitivity is comparable to leading limits from equivalence principle tests, potentially exceeding these in a specific mass range. Furthermore, we set new constraints on Yukawa gravity. The fifth force-induced precession increases with the orbital semi-major axis in the limit of a small mass $m$, motivating the study of objects further away from the Sun. We discuss future prospects for extending our study to more than a million asteroids, including NEOs, main-belt asteroids, Hildas, and Jupiter Trojans, as well as trans-Neptunian objects and exoplanets.