Phases of the Moon
Created by Mrs. Bodine-Donahue

The lunar month is the 28 days it
takes to go from one new moon to the
next. During the lunar month, the
Moon goes through all its phases.
We only see
the Moon
because
sunlight
reflects back
to us from
its surface.
During the course of a month, the Moon
circles once around the Earth. If we could
magically look down on our solar system,
we would see that the half of the Moon
facing the Sun is always lit. But the lit side
does not always face the Earth!
As the Moon
circles the Earth,
the amount of the
lit side we see
changes. These
changes are known
as the phases of
the Moon and it
repeats in a
certain way over
and over.
Moon Phase Descriptions...
Although this cycle is a continuous
process, there are eight distinct
stages, called phases. These phases of
the Moon, in the sequence of their
occurrence (starting from New Moon),
are shown below.
New Moon - The Moon's dark side is facing the
Earth. The Moon is not visible. The lighted side
of the Moon faces away from the Earth. This
means that the Sun, Earth, and Moon are almost
in a straight line, with the Moon in between the
Sun and the Earth. The Moon that we see looks
very dark.
Waxing Crescent Moon - As the Moon moves
around the Earth, we get to see more and more of
the illuminated half, and we say the Moon is
waxing. At first we get a sliver of it, which grows
as days go by. This phase is called the crescent
moon.
Quarter Moon - A week after the new moon,
when the Moon has completed about a quarter
of its turn around the Earth, we can see half
of the illuminated part; that is, a quarter of
the Moon. This is the first quarter phase.
Waxing Gibbous - The Moon appears to be more
than one-half but not fully illuminated by direct
sunlight. The fraction of the Moon's disk that is
illuminated is increasing. This Moon can be seen
after the First Quarter Moon, but before the Full
Moon. The amount of the Moon that we can see
will grow larger and larger every day. ("Waxing"
means increasing, or growing larger.)
Full Moon - The Moon's illuminated side is facing
the Earth. The Moon appears to be completely
illuminated by direct sunlight. The lighted side of
the Moon faces the Earth. This means that the
Earth, Sun, and Moon are nearly in a straight line,
with the Earth in the middle. The Moon that we
see is very bright from the sunlight reflecting off
it.
Waning Gibbous Moon - From now on, until it
becomes new again, the illuminated part of the
Moon that we can see decreases, and we say it's
waning. The first week after full, it is called
waning gibbous. The amount of the Moon that we
can see will grow smaller and smaller every day.
("Waning" means decreasing, or growing smaller.)
Last Quarter - One-half of the Moon appears to be
illuminated by direct sunlight. The fraction of the Moon's disk
that is illuminated is decreasing. Sometimes called Third
Quarter. The left half of the Moon appears lighted, and the
right side of the Moon appears dark. During the time
between the Full Moon and the Last Quarter Moon, the part
of the Moon that appears lighted gets smaller and smaller
every day. It will continue to shrink until the New Moon.
Waning Crescent - The Moon appears to be partly
but less than one-half illuminated by direct
sunlight. The fraction of the Moon's disk that is
illuminated is decreasing. This Moon can be seen
after the Last Quarter Moon and before the New
Moon. The crescent will grow smaller and smaller
every day, until the Moon looks like the New Moon.
A while after four weeks the illuminated half of
the Moon again faces away from us, and we come
back to the beginning of the cycle: a new moon.
Moon Phase Misconception...
"The most common incorrect reason given for the cause of the
Moon's phases is that we are seeing the shadow of the Earth
on the Moon! But this cannot be correct: when the Moon passes
through the shadow of the Earth, we get a lunar eclipse.
Anyone who has seen a lunar eclipse, though, might remember
that the Moon actually passes through the Earth's shadow only
rarely, so that can't be why the Moon has phases. The real
reason for the Moon's phases depends on two things: the Moon
is round, and the angle it makes with the Earth and Sun
changes over its orbit."
- As Quoted From Bad Astronomy