Quick Notes

Quick Notes

Science Chapter 9: Phases of the Moon and Constellation
9.1 Phases Of The Moon
 
The Moon is the brightest natural satellite easily identifiable in the night sky. If the Moon is observed carefully, the shape of the Moon differs on different nights. The Moon does not emit light, but reflects the light of the Sun to reach our eyes. Like the Earth, the Moon rotates on its axis and at the same time revolves according to its orbit around the Earth. The moon rotates on its axis in 27 1/3 days from West to East, orbiting the Earth also in 27 1/3 days from West to East.
 
9.1  Phases Of The Moon
 
  • The duration of the revolution and rotation of the Moon are the same, causing us to always see the same surface of the Moon.
  • As the Moon orbits the Earth, we will see different parts of the Moon illuminated by the light of the Sun.
  • The Moon's orbiting around the Earth causes the visible shapes of the Moon to change.
  • The different shapes of the Moon are known as the Phases of the Moon.
 
Phases of the Moon.

  1. New Moon - the dark part of the Moon faces the Earth
  2. Crescent - A small part of the moon's surface is sunlit and faces the Earth
  3. Half-moon - Half part of the moon's surface is sunlit and faces the Earth
  4. Gibbous - Most of the moon's surface is sunlit and faces the Earth
  5. Full moon - The entire surface of the moon illuminated by the light of the Sun faces the Earth
  6. Gibbous - Most of the moon's surface is sunlit and faces the Earth
  7. Half-moon - Half part of the moon's surface is sunlit and faces the Earth
  8. Crescent - A small part of the moon's surface is sunlit and faces the Earth
 
Lunar calendar
  • The calendar we use is the AD Calendar which shows the position of the Earth during its orbit around the Sun.
  • The calendar constructed based on the phases of the Moon is known as the Lunar Calendar.
  • This calendar is the Islamic Lunar calendar known as Hijri Calendar.
Lunar Days Phase of Moon
1, 2 New Moon
3, 4, 5, 6 Crescent
7, 8, 9, 10 Half-moon
11, 12, 13, Gibbous
14, 15, 16 Full moon
17, 18, 19, 20 Gibbous
21, 22, 23, 24 Half-moon
25, 26, 27, 28 Crescent
29, 30 New Moon