Why can’t you always see a full moon? The sun shines on the moon, just
as it shines on the earth. At any given time, half of the moon is in daylight,
and it’s night on the other half. We see only portions of its daylight half.
So each night (or day) of the month, we see a slightly different phase of the moon. The reason behind the
observer's
changing view of the moon is the fact that the moon is constantly revolving
around the earth.
The new moon phase is when the illuminated side of the moon faces away form
the earth. From earth we can not observe the reflected sunlight off the moon's
surface. Each day we see more and more of the lighted surface. We are now in the
waxing crescent phase. Waxing moons are moons that are increasing in apparent
size of reflected area visible from the earth. When we can see half of the
reflected surface of the moon (that would be 1/4), we are at a 1st quarter moon.
The moon seems to grow bigger from right to left. After the full moon it seems
to decrease in size from right to left.
The phase of the moon between 1st quarter and full is called a
waxing
gibbous. The moon continues to grow until we can see the entire illuminated
surface of the moon at the full moon phase. The waning gibbous follows with more
of the lit surface showing up on the left side. The 3rd quarter (left side
showing) comes into view looking the exact opposite of a 1st quarter right side
showing). The waning crescent comes into view getting smaller and smaller until
we start the cycle over again with the new moon.
Quiz
