As we build our Solar System, it will be useful to abstract out a
Planet class to be used for each planet.
Planets have a number of different attributes that define their unique characteristics in addition to their texture resource IDs. Planets have a distance from the Sun, size (radius), and an orbital speed. Planets all orbit around the Sun as their origin.
- The distance will be its distance from the Sun measured in millions of kilometers.
- The radius will be the planet's size in kilometers (actually in millions of kilometers, to be consistent).
- Rotation is the rate at which the planet rotates about its own axis (one of its days).
- Orbit is the rate at which the planet rotates about the Sun (one of its years). We will assume ...