Moon Phases

Half of the Moon is always lit up by the sun Half of the Moon is always lit up by the sun. As the Moon orbits the Earth, different parts are lit by the sun

We ALWAYS see the SAME SIDE of the moon. The revolution of the Moon around the Earth makes the Moon look as if it is changing shape in the sky.  We ALWAYS see the SAME SIDE of the moon.

The phase of the Moon that we see depends on the orientation of the Earth and Moon, relative to the Sun. The Moon's phases are caused by the part of the lit half we can see on earth.

The moon orbits the Earth once in about 28 days The moon orbits the Earth once in about 28 days. This changes which half of the moon is lit by the sun and how much of that part can be seen from the earth.  

The Moon changes in position in the sky each day. The Moon changes in appearance, these changes are called phases.

The length of time from New Moon to New Moon is called the LUNAR MONTH or SYNODIC PERIOD of the Moon. It is 29.53 days. The Moon rises in the east and sets in the west daily, but its position in the sky moves EASTWARD by about 13 degrees per day.

The side we cannot see on Earth is lit by the sun. New Moon The side we cannot see on Earth is lit by the sun.

The side of the Moon facing the Earth is lit by the sun. Full Moon The side of the Moon facing the Earth is lit by the sun.

Waxing Waxing means to increase in size or grow larger. From New Moon To Full Moon

Waning Waning means to decrease in size or grow smaller. From Full Moon to New Moon

Gibbous Gibbous is when more than 50% of the moon is visible

Crescent Crescent is when less than 50% of the moon is visible.

Quarter Moon Half full

New Moon

Waxing Crescent

First Quarter

Waxing Gibbous

Full Moon 20

Waning Gibbous

Last Quarter

Waning Crescent

New Moon