Sunday, 11 December 2011

Phases of the Moon

1. a) Phases of the Moon are caused by the different positions of the Sun and the Earth to the 
    b) These changes occur when the Moon revolves round the Earth. At the same time, the Earth and Moon revolve round the Sun.
2. As the Moon is illuminated by the Sun, half of the Moon is bright while the other half is dark.
3. From Earth, the Moon can be seen at different angels on different nights.
4. Therefore, different shapes of the Moon are seen on different nights.
5. The shape of the Moon depends on how much of the illuminated part of the Moon faces the Earth.
                                                                     Phases of the Moon

Saturday, 10 December 2011

Day and Night

The occurance of day and night

1. The rotation of the Earth on its axis takes place at all times. However, the position of the Sun is always fixed.
2. At any one time,
    a) half of the Earth is facing the Sun. This part of the Earth receives sunlight and experiences day.
    b) half of the Earth is facing away from the Sun. This part of the Earth does not receive sunlight and, therefore, is in darkness. 
3. The Earth takes 24 hours to complete one rotation. during every 24 hours :
    a) half of the Earth experiences day
    b) half of the Earth experiences night.


Monday, 5 December 2011

Rotation Of The Moon

1. Like the Earth, the Moon also rotates on its axis from west to east.
2. While rotating on its axis, it also revolves round the Earth.
3. The time taken for the Moon to make one rotation is the same as the time taken for it to go round the Earth. Therefore, from the Earth, we always see the same side of the Moon.
4. The Moon takes 27 1/3 days to make one complete rotation on its axis.
5. The Moon takes the same time (27 1/3days) to make one complete revolution around the Earth.

Rotation Of The Earth

1. The Earth spins on its axis like a spinning top. This spinning motion is called rotation.
2. An axis is an imaginary line that goes through the centre of the Earth. It links the north pole to the south pole.
3. The earth rotates from west to east.
4. a) The Earth takes 24 hours to make one complete rotation.
    b) It takes one year to make one complete movement round the Sun. This movement is called a revolution.