A description of why and how the shape of the Moon appears to change when seen from the Earth. The Moon is lit by the Sun. Half of the Moon is lit and half is dark. When the dark side of the Moon is facing Earth we cannot see it; this is called a new moon. As the Moon starts to orbit Earth we can see more and more of the lit side. At various stages in its orbit it is called a crescent moon, a quarter moon and a full moon. It is called a full moon when we can see all of the sunlit side of the Moon.

First broadcast:
12 October 2007

This clip explains the way in which the moon appears to change shape as it orbits Earth. Using ping pong balls painted coloured/ half black, ask the children to reproduce the demonstration they observed on the clip, noticing how the proportion of white of the ping pong ball increases as it orbits them. Children could record the changing shape of the moon in diagrammatic form. A moon diary, recorded over a month, would be a useful way of consolidating their learning.