i can only offer my own set of terms and henceforth adhere to them with consistency : our sun i will refer to by name , sol ; any star will be referred to as a sun if it nourishes planets and i am describing a setting that is near enough to the star so that its stellar wind dominates the interstellar medium ; the moon i will refer to by name , luna ; in general , the moon of any planet should be referred to as a natural satellite but i will still refer to these bodies as moons ; the word `` planet '' will refer only to a solid , rocky planet and i will never be so absurd so as to use the same word to refer to a gas giant . )