An orbit is the gravitationally curved path of an object around a point in space. The current understanding of orbital motion is from Albert Einstein’s general theory of relativity. This accounts for gravity due to curvature of space-time which orbits following geodesics.
There are some common ways to understand orbits:
- As objects move sideways, it falls toward the central body. However, it moves so quickly that the central body will curve away beneath it.
- A force, like gravity, pulls the object into a curved path as it attempts to fly off in a straight line.
- As the object moves tangentially, it falls toward the central body. However, it has enough tangential velocity to miss the orbited object and will continue falling indefinitely.
Our solar system there is many things which orbit the Sun, planets, dwarf planets, asteroids, comets and space debris. The Sun is called the barycenter in elliptical orbits. Some bodies, such as comets, are not gravitationally bound to the star and therefore are not considered part of the star’s planetary system.