Why are seasons caused by the tilt of the earths axis of rotation?
The tilt of the earth causes the angle of the sun at its hightest point from day to day to change throughout the year. It also causes the periods of daylight to change. When daylight is longer in the north, it is shorter in the south, and vice versa. This is why it is summer in one hemisphere and winter in the other. The distance between earth and sun has little or no affect on the seasons.
