Surface tracking systems and methods for tracking a first wellbore relative to a non-geological target in a subterranean formation by determining characteristics of gravity anomalies related to the first wellbore and the non-geological target. The system includes a gravity sensor located at the Earth's surface and an information handling system operable to analyze the first and second gravity anomalies to determine a position and the trajectory of the first wellbore relative to the non-geological target. The systems and methods may also include the ability steer a trajectory of the first wellbore relative to the non-geological target.