Figure 12-34Mercury’s Orbit Explained by General Relativity The location of Mercury’s perihelion (its position closest to the Sun) and its long axis of orbit change, or precess, with each orbit. This change occurs because of the gravitational influences of the other planets plus the curvature of space as predicted by Einstein’s theory of general relativity. The amount of precession is inconsistent with the prediction of the orbit made by Newton’s law of gravity alone.