CHAPTER 36 – THE EARTH-SUN-MOON SYSTEM 7. Third quarter: Only half of the side of the Moon that can be seen from Earth is lit by the Sun.
8. Waning crescent: The Moon now appears as a crescent again. It continues to wane until none of the side of the Moon facing Earth is lit by the Sun and the lunar cycle begins again with a new moon.
A full lunar cycle – from new moon to new moon – takes approximately one month (29.5 days) to complete.
:Fig. 36.12 The full moon phase of the lunar cycle
CONCENTRATE! Waxing means ‘getting bigger’.
Waning means ‘getting smaller’. Third quarter
Rays from the Sun
Waning crescent Waning gibbous
:Fig. 36.13 The third quarter phase of the lunar cycle
11. Explain why we only ever see the same side of the moon from Earth. 12. Explain why we cannot see a new moon from Earth. 13. Explain the terms ‘waxing’ and ‘waning’ with reference to the lunar cycle.