Describe the motions of bodies in the solar system?

Answer 1

All massive bodies in the solar system are in motion, even the Sun. The planets occupy elliptical paths with a common center of gravity with each other and the Sun (barycenter) at one of the foci of the ellipse, the path being called an orbit; the motion of the planets in the orbit is counterclockwise as seen from above the Earth's north pole looking down at the orbits and per Kepler's laws at its closest approach to the sun will move slightly faster and at greater distance moves slightly slower - this effect also consistent with the length of the orbital period or year, increasing distance resulting in longer years. The axis of the ellipse also precesses or advances slightly with each orbit (per predictions of Einstein's General Relativity). Other bodies not in orbit directly around the Sun may be in orbit around a planet and orbit their primary while the latter is in solar orbit. Some objects such as comets have highly elongated orbital paths. All objects also have some intrinsic angular momentum, rotating on their own axis (day). All objects interact and are drawn by other objects to a greater or lesser degree mediated by the force of gravitational pull proportional to mass and inversely proportional to the square of the distance; these effects creating irregularities in their orbits (perturbations) some of which result in stable harmonics known as orbit resonance. Spin-orbital resonance may also arise from tidal force and affect the relationship between rotational and orbital periods.

There are other types of motion but these are some of the basics.