Final answer:
The position of the Earth, Sun, and Moon changes due to Earth's rotation, the Moon's revolution, Earth's axial tilt, and the elliptical orbit of Earth around the Sun. These movements result in daily changes such as day and night, and long-term changes such as the seasons and the phases of the Moon. Tides are a significant result of the gravitational interactions between Earth and the Moon.
Step-by-step explanation:
The positions of the Earth, Sun, and Moon change throughout the year due to several astronomical phenomena:
Rotation of the Earth: Earth completes a rotation on its axis every 24 hours, resulting in day and night. This rotation does not significantly change the positions of Earth, Sun, and Moon with respect to each other in the long term, but affects daily appearances.
Revolution of the Moon: The Moon orbits Earth approximately once a month, while maintaining a consistent face towards Earth due to synchronous rotation. The changing angles of illumination by the Sun produce the Moon's phases.
Axial tilt of the Earth: Earth's axial tilt causes the Sun to move north and south in the sky as the seasons change. This movement is due to the inclination of the ecliptic, the plane in which Earth orbits the Sun.
Earth's elliptical orbit around the Sun: The center of mass of Earth and Moon orbits the Sun in an elliptical path with 'wiggles' influenced by the Moon's gravity. The detection of similar wiggles in the motion of other stars is evidence of planets orbiting them.
In addition to these motions, tides on Earth are a noticeable effect of the Moon's gravitational pull, with the tidal bulges aligning with the Moon as it orbits. The Sun also contributes to the tides, albeit less so despite its larger gravitational force, because the Moon's proximity gives it a greater influence on Earth's water.