Poddar, Tanmay KumarTanmay KumarPoddarPachhar, DebashisDebashisPachhar2025-08-222025-08-222023-02-012331-8422http://arxiv.org/abs/2302.03882https://d8.irins.org/handle/IITG2025/18473Ultralight Axion Like Particle (ALP) can mediate a long range monopole-dipole macroscopic force between Earth and Sun if Earth is treated as a polarized source. There are about 1042 number of polarized electrons in Earth due to the presence of the geomagnetic field. The monopole-dipole interactions between electrons in Earth and nucleons in Sun can influence the perihelion precession of Earth, gravitational light bending and Shapiro time delay. The contribution of monopole-dipole potential is limited to be no larger than the measurement uncertainty. We obtain the first bound on monopole-dipole strength from single astrophysical observations. The perihelion precession of Earth puts the stronger bound on monopole-dipole coupling strength as gSgP≲3.62×10−11 for the ALP of mass ma≲1.35×10-18 eVen-USALPMonopole-dipole macroscopic forceShapiro time delayPolarized sourcePerihelion precessione-Printe-Print123456789/615