One effect that the Moon's orbit has on our planet is the way we see the Moon. This is called the phases of the Moon. There are eight different phases of the Moon. These phases are called, in order, new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter and finally, waning crescent. It takes approximately 27 days for the moon to complete this cycle. Approximately every 2.7 years two full moons will occur in just one month. This event is very rare and is referred to as a Blue Moon. From earth we always see the same side of the moon. The diagram above illustrates that the sunlight coming from the sun reflects on the moon and that is why we are able to see it from Earth.
The eight phases:
(photography credited to my dad)
New Moon:
The Moon is not visible when it is in this phase. This is because it is only visible when it is during the day and nonvisible during the nights, which are the opposite times of when we view the Moon. The side of the Moon that is shown during this phase is not lighted up or illuminated. This phase is when the Moon is in-between the Earth and the Sun.
Waxing Crescent:
This phase is the beginning of the Moon appearing to the Earth. Every night, a few minutes after sunset, this lunar silver is visible to us on Earth. This phase gets the term ‘waking’ because a little bit more of the Moon is visible for a longer amount of time each night.
First Quarter:
During this phase, half of the Moon is visible for the first half of the night, while it is down for the second half, leaving the sky very dark.
Waxing Gibbous:
By this phase approximately ¾ of the face of the Moon can be viewed and this is the reason why this phase is given the name Gibbous. While the Moon is in this phase it will remain in the sky for almost all of the night.
Full Moon:
A full Moon is where the whole face of the Moon can be viewed. At the start of the night is when a full Moon rises and it sets around the beginning of the new morning.
Waning Gibbous:
The term given to the word ‘waning’ means that the face of the Moon viewed from Earth appears smaller each night. This phase is often compared to the Waxing Gibbous phase as for both of them enable us to see all but a silver of the Moon. The only difference between the two however, is that with the Waxing Gibbous we see more of the Moon each night.
Last Quarter:
During a Last Quarter Moon we can see half of the Moon's lighted surface. This phase appears as a vertically flipped first quarter.
Waning Crescent:
This phase is the final phase of the Moon's eight phases. During this phase, only a small silver of the Moon can be seen from Earth and only if it is right before the beginning of the morning. Each night less of the Moon is visible for less time.