Simulations with Q_e = 300, showing three cases with different initial Earth obliquities (61°, 65°, and 70°). In each panel, the lower middle subfigure shows h vs. time, where h is the difference between the longitudes of ascending nodes of Earth’s equator and the lunar orbit, both measured on the ecliptic plane. The angle h is a natural measure of whether the lunar orbit is aligned to Earth’s equator. During the LPT, the amplitude of h gradually grows from near-zero to π.