Peculiarities of the Earth and Moon motion

The video shows the movement of the center of mass of the Earth-Moon system around the Sun and the rotation of the Earth and Moon relative to it. The phenomenon of precession of the lunar orbit is also clearly shown.

Just a few centuries ago, it was believed that the Earth was stationary, and the Sun and planets revolved around it. Now we know that it is the planets that move around the Sun. It is usually said of our planet that the Moon revolves around it, and the Earth itself moves around the Sun. However, it is more correct to say that the center of mass of the Earth-Moon system moves around the Sun, with both the Earth and the Moon revolving around their common center of mass.

The video shows how our planet oscillates relative to its common center of mass with the Moon as it moves around the Sun. The period of the Earth's oscillations around this barycenter coincides with the period of the Moon's rotation around it and is 27.3 days. While you are “motionless” reading this text, you are actually moving around the Sun along a very complex trajectory. While on the Earth's surface, you make a revolution around its axis in one day. At the same time, you oscillate relative to the Earth-Moon barycenter in about one month and make a revolution around the Sun in one year. The barycenter is inside the Earth, that is, the radius of oscillations is slightly smaller than the radius of the planet itself. The Moon moves around the barycenter along a similar trajectory. But this trajectory is mirrored and is larger in size by the same number of times as the mass of the Earth is greater than the mass of the Moon.

The video also clearly shows the phenomenon of precession of the Moon's orbit. Precession is the slow rotation of the lunar orbital ellipse in space over 8 years and 10 months. The plane of the Moon's orbit also rotates and makes a full revolution in about 18 years and 7 months. Lunar precession occurs primarily because the Moon is affected by the gravity of the Earth, as well as the gravity of the Sun. Moreover, the gravity of the Sun acting on the Moon is more than twice as great as the gravity of the Earth. In addition to the Sun, the precession of the lunar orbit is also contributed to by the non-spherical shapes of the Earth and the Moon. The precession of the lunar orbit explains the cyclicality of solar eclipses. At the same time, the Moon is gradually moving away from the Earth by about 3.8 meters per century. This will lead to the fact that in about 750 million years it will become impossible to observe total solar eclipses from the surface of our planet…

Throughout this video, the sizes of the Earth, other planets, the Sun, and the Moon are shown as greatly exaggerated compared to the distances between the bodies. The speed of the Earth's rotation around its axis is shown as greatly reduced compared to the speed of the celestial bodies' motion in their orbits.

Modeling and visualization were performed by the author of this publication using software of his own design. The calculations took into account the mutual influence of the Sun, all planets of the Solar System and the Moon. Relativistic effects were also taken into account in the calculations.