Activity

Aim: To simulate and observe the phases of the Moon

Procedure:

1     This activity must be carried out in a dark room.
2     A stick is pierced through the centre of a polystyrene ball to represent the Moon.
3     An electric torch is placed in the room to represent the Sun.
4     The polystyrene ball is held by the observer at arm's length between the torch and his eyes.
5     The half surface of the ball facing the observer is observed.
6     The observations are recorded in the form of drawings.
7     Together with his arm, the observer turns 45 degree to the left (anticlockwise).
       He observes the surface of the ball facing him and records its apperarance.
8     Step 7 is repeated for all the other positions given in the following diagram.

Inferences:

1     We see different parts of the Moon at different times because the angles between the Moon, the Earth and the Sun are changing all the time.

2     When the Moon is farthest from the Sun, half of the surface of the Moon is illuminated. This is known as the full moon.


Conclusion:

The phases of the Moon are caused by the movement of the Moon around the Earth and its changing position relative to the Sun.