self-luminosity meaning in Chinese

自发光性

Changed of moon phases are brough about by the non - self - luminosity and the opacity of the moon . as the moon is a spherical body , sunlight can only illuminate half of the moon . viewing from different directions , the moon will appear to take the shapes of a circle , a semi - circle , a crescent , a gibbous or even completely invisible at all when its dark side faces the earth
由于月球本身不发光，只是反射太阳光，所以当月球运转时，月球地球和太阳三者的相对位置便会不断变化，因此，地球上的观测者所见到月球被照亮的部分也在不断变化，从而产生不同的月相