Earth–Moon distance compared with the Keplerian model. The normalized distance between the Earth and the Moon computed using the latest planetary ephemerides, DE440, is compared with the Keplerian model in the freely falling reference frame centered on the Earth–Moon barycenter. The tidal pull fluctuates at the perigee crossing for the Moon’s orbit around the Earth as the Earth–Moon barycenter orbits the Sun. As a result, the actual Earth–Moon distance fluctuates compared to the Keplerian model at the perigee crossing. The tidal acceleration on the moon due to the Earth and Sun is given in Equation (A11). DE440 accounts for the first term in Equation (A11), whereas the Keplerian model does not include any tidal terms. The second term in Equation (A11) is much smaller than the first term and is due to the Sun’s effect on the Earth–Moon barycenter. The phase offset between the Earth’s orbit around the Sun and the amplitude modulation of the Earth–Moon distance is due to the inclination of the lunar orbit (∼5°) with respect to the equatorial coordinate system, with the xy-plane coinciding with the Earth’s equator.