Look at Fig. 17.7 carefully and answer the following question:

(a) In which part of the sky would you see the full moon in the evening?

(b) In which part of the sky would you see the crescent moon in the evening?

(a) Different phases of the moon are observed because of reflection of the Sun. The part of the moon reflecting the Sun's light become visible and hence we can observe different conditions like crescent moon, full moon, new moon etc.

In the given figure the full moon condition in the evening will be observed in the eastern part of the sky. (Assuming North upwards).

(b) When only a small arc-shaped section of the moon is illuminated by the Sun then that stage is known as crescent moon stage. In this case the moon is sickle shaped, that is, broad in the middle but tapering at the edges.

In the given figure, the crescent moon condition in the evening will be observed in the western part of the sky (Assuming North upwards).