According to Newton's first law, the center of mass of this system must continue along its original path since there was no external force to change its direction. Placing a planet in orbit without moving the sun would offset the center of mass of the system and violate Newton's first law. This means that viewed from a distance, nothing has changed and the energy of the explosion that separated these masses in space is still in the system. From the angular motion of the planet about the sun, one infers the presence of energy in the Spin dimension. To illustrate this, one needs two energy circles that operationally are perpendicular to each other.
Spin acts as a catalyst.
To see their relationships, one needs to look at a general ellipse. At time zero, the planet is to the right along the X axis. As the planet moves CCW a quarter cycle in its orbit, energy converts to Spin. The line joining the planet to the sun sweeps through equal areas in equal times. To understand this second law, let the planet sweep out areas while traveling at different angular velocities, i.e., different omegas.