The Moon Phases

What are the names of the moon phases?

First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Third Quarter, Waning Crescent, New Moon, Waxing Crescent.

Why do we see phases of the moon?

We see phases of the moon because the moon revolves around the Earth.

How long does each moon phase lasts?

Each moon phase last about three to four days.    

Waxing and Waning

What's  the difference between Waxing and Waning?

Waxing > getting bigger

Waning > getting smaller

How much percent is shown of each moon phase?

New Moon = 0%                Quarter Moon = 50%

Full Moon =  100%          Crescent = 25%

Gibbous = 75%                                                ( Because rotation equals revolution, we only                                                                                      see one side of the moon.)

One revolution = 28 days

One rotation = 28 days

                                                  GALILEO GALILEI

In November 1609, Galilo decided to make an in-depth study of the moon with his improved telescope with 20x magnification. From November 30th to December 18th of that year, he examined and drew the moon and described that research in his book Sidreus Nucius. His observations led him to think that moon was anything but perfect. He observed as time passed, these and other spots changed, either getting lighter and eventually disappearing or getting darker and more distinct. Galilo also observed that the interface between the light and dark sides of the moon was rough and uneven, rather than perfectly smooth as would be expected on a perfectly smooth sphere.

"have a dark part on the side toward the Sun while on the side opposite the Sun they are crowned with brighter borders like shining ridges."

(Sidereus Nuncius, p 41)

             Here's a video of the transitions of each moon phase: