Friday, 19 October 2012

Phases of the Moon

  • The Moon is the brightest object in the night sky.
  • However, it does not emit light.
  • The Moon appears bright at night because it reflects light from the Sun to the Earth.

Phases of the Moon

→ The revolution of the Moon around the Earth makes the Moon seem to change its shape in the night sky. Actually it does not. This is caused by the different angles we see from the bright part of the Moon's surface. The Moon goes through 4 major shapes during a cycle that repeat itself every 28 days.
→ It is an appearance of the illuminated portion of the Moon.

*First Quarter &Third Quarter-Half Moon

 → New Moon
  • part of the Moon which is not illuminated faces the Earth.
  • the Moon is not visible.
  • the lighted side of the Moon faces away from the Earth.
→ Crescent Moon
  • the Moon is less than half illuminated by the Sun.
  • can be seen after the new Moon.
  • the crescent will grow larger and larger everyday.
→ Half Moon
  • half of the illuminated side of the Moon is visible.
  • the half appeared lighted and the other half appears dark.
  • looks like half a circle.
→ Full Moon
  • the Moon's illuminated side is visible.
  • the lighted side faces the Earth.

Wednesday, 17 October 2012

The Earth, The Moon and The Sun

Earth rotate on its axis from the west to the east. It takes 24 hours to make one complete rotation.

→ How long does the Earth take to move around the Sun?

√  The Earth also moves around the Sun at the same time. It takes one year to move around the Sun.

The Moon also rotate on its axis. It takes about 28 days to make a complete rotation. At the same time, the Moon moves around the Earth. It also takes about 28 days to move around the Earth.

  • In early morning and afternoon, the Sun rises on the horizon and makes long shadows.
  • At noon, the Sun is directly overhead and makes short shadows.
  • The rotation of the Earth on its axis causes the length and position of a shadow to change.

The Sun is the centre of our solar system. The Earth and the Moon move around the Sun at the same time.

Day and Night

The Earth rotates on its axis. This rotation causes day and night. 
The part of the Earth that is facing the Sun experiences daytime.
The part of the Earth that is facing away from the Sun experiences nighttime.

Day and night, Earth's Rotation