This is due to the fact that moon is locked in 1-1 spin orbit coupling around the Earth.
The Moon spins at the rate of one rotation every 28 days, which coincidentally happens to be just how long it takes the Moon to orbit the Earth once.
Rotion matches it's revelution.
Full Moon
Full Moon
The moon is between the sun and earth and reflects light back toward the sun
The moon is between the sun, and Earth and reflects light back toward the sun.
The moon is between the sun and earth and reflects light back toward the sun
new moon
Full Moon
Full moon
Full Moon
Full Moon
A solar Eclipse. The moon blocks the sun out to observers on Earth.
There are times that the umbra of the moon fails to reach the Earth. This is when the moon is at apogee. When this happens, observers witness an annular, or ring, eclipse. During anannular eclipse, observers in the umbra see a thin, bright ring around the moon.
The moon is visible to us because it reflects the sun's light.
The moon is between the sun and earth and reflects light back toward the sun
The moon is between the sun and earth and reflects light back toward the sun
The moon is between the sun, and Earth and reflects light back toward the sun.
Half of the moon is always lit up by the sun at any given time, and the moon orbits the Earth so us observers on Earth will see different amounts of the moon lit up. These different "shapes" we see are called the phases of the moon.