Look into the sky and you will see the austere motion of spherical bodies as if they perform the perfect space dance. Planets, moving along orbits, experience a lot of effects: the changing of seasons, solar storms, space radiation, however they don’t reduce the tempo for a moment. Comets and asteroids attempt to break the lasting balance at times, but, even if they exert a shattering impact to the surface, they rarely can affect the rotating velocity of graceful dancers. They aim to continue the dance endlessly.