English: Normal gravity for a system with GM = 1, a = 1, b = 0.8, ω = 0.3. The level ellipsoid is shown in red. The blue lines are contours of constant gravity potential (gravitational + centrifugal); the contour spacing is constant and equal to 1/20 of the difference between the potentials on the ellipsoid and at the geostationary point (R = 2.2536, Z = 0). The green lines are stream lines for the gravity; these are spaced at intervals of 10° in parametric latitude on the surface of the ellipsoid.