Everything in the universe operates on one or more cycles. Nothing is fixed in place; the motion of the heavenly bodies is a function of the forces acting on them. Any object in the Milky Way Galaxy will rotate around the galactic center with an orbital velocity and cycle which are a function of two things: (1) the mass of the galaxy; and (2) the distance of the object to the barycenter (center of mass) of the galaxy. The same rule applies to the orbits of the planets around the Sun.
Note that while many orbits are circular or nearly so, that is not required and indeed some objects (like comets, in the solar system) have highly eccentric orbits, and some may indeed follow 'one-pass' hyperbolic or parabolic paths -- they travel through the solar system, approach the Sun, 'slingshot' past it, and then depart never to return.
Everything in the universe operates on one or more cycles. Nothing is fixed in place; the motion of the heavenly bodies is a function of the forces acting on them. Any object in the Milky Way Galaxy will rotate around the galactic center with an orbital velocity and cycle which are a function of two things: (1) the mass of the galaxy; and (2) the distance of the object to the barycenter (center of mass) of the galaxy. The same rule applies to the orbits of the planets around the Sun.
Note that while many orbits are circular or nearly so, that is not required and indeed some objects (like comets, in the solar system) have highly eccentric orbits, and some may indeed follow 'one-pass' hyperbolic or parabolic paths -- they travel through the solar system, approach the Sun, 'slingshot' past it, and then depart never to return.
Johannes Kepler first described the motion of objects in space mathematically a bit over 400 years ago: https://en.wikipedia.org/wiki/Kepler_orbit
You definitely know your astronomy : )
Thanks for the lesson!❤️