Moon phases - understanding them
Just looking at the moon from the earth, it would be almost
impossible to figure out what is happening. It appears that the moon is
orbiting around the earth about once a day. Science has proven that the
moon does orbit the earth, but not once a day but closer to once a month.
What is really happening is our earth is spinning once a day which makes
it appear that the moon is going around us once a day.
The moon goes around the earth approximately one time every 29 1/2 days.
The moon always shows the same side toward the earth. We never see the
side facing away from us.
The moon itself does not have any light. Its' light is reflected from
the sun. The sun always shines on the moon and half of it is always illuminated.
What we see depends on where the moon is in relation to us and the sun.
When the moon is directly between earth and the sun, it is considered
the new (dark) moon. During this phase, the sun shines its' light on the
part of the moon we can't see, so we don't see any illumination. As the
moon goes further around the earth, the sun shines its' light on more
of the moon that we can see. When the moon moves half way around the earth,
the earth is between the sun and moon. This is when the half that we see
is totally illuminated, thus the full moon.
One of the confusing things to me is the terminology of the quarters.
The first quarter is really the first half moon and the third quarter
is really the last half moon. It makes sense if you think about quarters
being a fourth of the phase, but it is easy to try to associate quarter
with amount of illumination instead of the actual phase. Another reason
it is confusing is because the quarters start with zero (although you
probably won't see it listed as a quarter). The first quarter starts at
the half moon getting fuller (waxing) until the full moon. The second
quarter starts at the full moon and the illumination gets smaller (waning)
every day. The third quarter starts with the half moon waning and ends
with the new moon. There is no "fourth quarter".
If you read the terminology in the previous article, I mentioned that
the crescent is less than half illumination and gibbous is more than half
illumination. We also saw that waxing means getting fuller and waning
is just the opposite. Here is the complete phase with terminology:
1: New moon (dark)
2: Waxing crescent (less than half moon - right side illuminated)
3: 1st quarter (half moon - right side illuminated)
4: Waxing gibbous (more than half moon - right side illuminated)
5: Full moon (2nd quarter)
6: Waning gibbous (more than half moon - left side illuminated)
7: 3rd quarter (half moon - left side illuminated)
8: Waning crescent (less than half moon - left side illuminated)
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Judy Talley caught this fish while fishing with guide
Richie White on 2/26/06.
See a different trophy bass on every page of this site.
Professional Guide
Richie White
(903) 439-2266
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