In depth description of the Moon/s phases and why they are as they are. Uses some great internet animations of various situations explaining why we see what we see from Earth. Also discusses the tides and why they are caused by the moon's gravity.

1. Phases of the Moon
By Moira Whitehouse PhD

2. If you look at the sky, you will notice the shape of
the Moon changes each night. These different
views are called the phases of the Moon.

3. Let’s look at the phases of the Moon on a
calendar for February, 2013. Notice that
the change from phase to phase is very
gradual and takes about a month for the
whole cycle.
http://www.moonconnection.com/moon-february-2013.phtml

4. What causes the Moon's phases?
The Moon goes through phases (the view seen
from Earth at various times in the Moon cycle)
because:
1) the Moon is revolving around the Earth,
2) the Moon is reflecting sunlight towards
the Earth.

5. Interestingly, the same half of the Moon is
always in sunlight, (now think about that) and
the other half if it is always dark.
For this reason, we can see only the portion
that is lit, which, depending on its position in
the orbit, usually gives us a view of only part
of the Moon.

6. Although it is really a continuous and
gradual change, there are eight
recognized phases that the Moon goes
through and they always occur in the
same order.
In this repeating pattern the Sun's reflected
light moves across the surface of the
Moon, in our view, from right to left.

7. The Moon
changing
phases
quickly over
28 days
(about a
month).

8. The phases of the Moon are:

9. As shown in the diagram, the new moon
occurs when the Moon is positioned
between the Earth and Sun. The entire
illuminated
(lit up) side of
The Moon is on
the back part
of the
Moon–
the half that
we cannot see.
http://www.wiseg
orilla.com

10. The first quarter and third quarter moons
(both often called a "half moon"), occur when
the Moon is at a 90 degree angle with respect
to the Earth
and Sun. So we are
seeing exactly half
of the Moon
illuminated and
half in shadow.
http://www.wise
gorilla.com

11. At a full moon, the Earth, Moon, and Sun
are approximately lined up, just as they are
in the new moon, but this time the Moon is
on the opposite
side of the
Earth. As a result,
the entire sunlit
part of the Moon
is facing us. The
shadowed portion
is entirely hidden http://www.wise
from view. gorilla.com
free clip art for
educational use

12. The first quarter and third quarter moons
(both often called a "half moon"), occur when
the Moon is at a 90 degree angle with respect
to the Earth
and Sun. So we are
seeing exactly half
of the Moon
illuminated and
half in shadow.
http://www.wise
gorilla.com

13. Although we
give names to
certain phases,
each night the
change is
actually
gradual.

14. Select Moon Phases in the following URL
for an outstanding animation of the Moon
and its phases.
Select “Moon Phases”
http://www.valdosta.edu/~cbarnbau/astro_de
mos/frameset_moon.html

16. http://astro.unl.edu/naap/lps/animations/lps.
html

18. The gravitational pull of the Moon, though
less than that of the Earth, is strong enough
to causes water in the oceans to shift slightly
toward the moon as it passes overhead. This
is seen as a rise or fall along the oceans
shores that we call the tide.

19. Tides
The level water on the beaches around the
world rise and fall every twelve hours.
When the water level is the highest it is
called high tide. When it is the lowest it is
called low tide.

20. high tide low tide

21. low tide
high tide

25. :
Review:
•Remember we give names to the various
phases of the Moon as seen from Earth,
but the rotation is continuous us, it never
stops at any phase.
•The gravity of the Moon’s huge mass
affects our oceans causing them to bulge
toward the Moon, causing the tides.