The Moon's Phases



A little history on the phases of the moon...
The moon and its phases have existed since the formation of the universe about 5 billion years ago. As long as the Earth, Sun, and Moon has been in rotation, phases have occurred. The phases of the moon have played a large part in ancient civilizations. The moon’s phases have influenced language, (the words, Monday, menstrual, and month) calendars’, and mythology. The earliest recording of the moon’s phases is dated back 15,000 years as a lunar calendar on a cave wall. During the fifth century BC Babylonian astronomers had recorded eighteen years worth of lunar eclipses.

So what are the phases?
There are eight different phases in the lunar cycle. These phases in order are the New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, and Waning Crescent. Each phase is named after the amount of the moon that is visible from Earth.

external image moon_phaseswith%20earth.JPG

But What Causes These Phases?
The relative position of the Earth, Moon, and Sun determine the phase. The Sun is always illuminating half of the moon, but as the moon revolves around the Earth, the illuminated portion of the moon facing the Earth changes. The Earth will never black sunlight from the moon because it rotates 5 degrees off the Moon’s axis.

And eclipses?
During certain times of the year, the Sun, Earth, and Moon do “line up”. When the Moon blacks the suns rays it is known as a Solar Eclipse, this occurs during New Moons. When the Earth casts a shadow on the Moon, it is known as a lunar eclipse and occurs during full moons. Partial eclipses can also occur.

So what?

The Moon’s phases are particularly important to understanding events on Earth. Tides are largely a result of the moons gravitational pull which changes as it rotates around the Earth. The moons gravitational pull is strongest on the side of the Earth nearest to the moon. On this side of the Earth, masses of water are pulled towards the moon, thus creating a tide. Not only is the Moon helpful in understanding Earth, but by observing the Moon, we can predict the actions of other planet’s moons.

Oh, and the moon is unique!
The moon is unique compared to other known satellite planets. The Moon is the Earth’s only natural satellite. It is also the fifth largest in the known universe. All of these things attribute to the vast differences between phases.

Any current events?

Recently no new knowledge has been gained and reported about the phases of the moon or their effects; However new discoveries are being made about the moon each day which could potentially enhance our knowledge of lunar phases. In 2008 small traces of water were found in lava beads brought back by Apollo 15. Using CHASE, water seemed to have reflected form the moon.

How do we know all of this?
Through observation from satellites and earth bound telescopes, we have obtained all we know about the moon’s phases.


My Personal Feelings about the moon’s phases…
I was initially intimidated by my topic. However once I started to research the phases, I was pleased to find relatively simple explanations. I found the information of the tides most interesting. I am interested to know how exactly they determined each phase. Ultimately my belief system was not change, rather solidified. Only a God as great as ours could create such a well oiled machine as the universe.


Work Cited: http://yuktirat.com/images/moon_phaseswith%20earth.JPG, http://aa.usno.navy.mil/data/docs/MoonPhase.php, http://www.moonconnection.com/moon_phases.phtml, http://www.harcourtschool.com/activity/moon_phases/