[Mak4228]

1) Phases of the moon are caused when the shadow of the earth falls on it. You know that moon is revolving round the earth and earth is revolving round the sun. To, understand you'll need three balls of different sizes. take basket-ball as sun, a smaller volley ball as earth and a base-ball, ball as the moon. Put the 'sun' , 'earth' and 'moon' in a straight line in the same order. Now, you can see that the shadow of the earth is falling on the moon which makes it completely invisible or partially visible. Various phases of moon can be seen while it revolves round the earth. The time when shadow of the earth does not fall on the earth, the moon is completely visible.2) Seasons on the earth are caused due to various reasons.a) Revolution of earth round the sun : The earth revolves round the sun. Its distance is a little responsible for the change of season.b) Rotation of earth on its own axis : Rotation on of the earth on its own axis causes winds to blow.c) Tilted earth : Earth is tilted about 23.5 degrees. This cause the area near the equator to heat up more and the area near the poles remain cold throughout the year. This is the reason behind the causation of water currents.All the above three factors are majorly responsible for the change of seasons. There are many more local factors which affect the seasonal change.