How many worlds are there? Count them. These fragments of the Solar System orbit some central point without colliding. They are satellites of a universe where gravity exists and the centripetal force keeps each at bay and at large. Life exists within and then there is space, void of all things necessary to sustain a living thing until the next spinning mass. Occasionally a cursory coalescence disturbs the cosmos and the stratosphere of two celestial bodies is shared. Then time and the speed of light pulls them apart to become a star somewhere out there in the blackness.