The Phases of the Moon
We have all wondered what causes the moon to go through phases. The best way to understand this process is by looking at a moon-sun diagram. This can be accessed through using Google. The best way to describe the moon phases is to realize that exactly one half of the moon is always illuminated by the sun. This is perfectly logical; however, in order to understand this concept we should visualize this on a diagram. This can be accessed at http://www.moonconection.com/moon_phases . At certain times we see both the sunlit portion and the shadowed portion of the moon---and that creates the various moon phases we are all familiar with. The best explanation is that the lunar phases are created by changing angles (relative positions) of the earth, the moon and the sun, as the moon orbits the earth.
Moon phases can be simplified by understanding them in this order: new moon and full moon, first quarter and third quarter, and the phases in between. The new moon occurs when the moon is positioned between the earth and the sun. At this time the three objects are in approximate alignment. At full moon the earth, moon, and the sun are in approximate alignment, just as the new moon, but the moon is on the opposite side of the earth, so the sunlit part of the moon is facing us. The shadowed part is entirely hidden from view. The first quarter and third quarter moons (also called half-moons) occur when the moon is at a 90 degree angle with respect to the earth and the sun. This allows us to see exactly half of the moon illuminated and half of the shadowed part of the moon.
Other fun moon facts: After a new moon and the sunlit portion is increasing, but less than half this is called waxing crescent. After the first quarter the sunlit portion is still increasing, but now more than half this is called waxing gibbous. After the full moon light is decreasing, so this is called waning gibbous. Following the third quarter this is known as waning crescent. And then the cycle begins again!
Moon's Orbit: You may think it takes about one month for the phases of the moon to take place, but actually, it is exactly 29.5305882 days This is the time required for the moon to move to the same position as seen by an observer on earth. If you were to view the moon from outside our solar system (for example from the stars) the time required would be 27.3217 days roughly 2 days less. If you find this interesting then try to figure out why this is?
Moon phases can be simplified by understanding them in this order: new moon and full moon, first quarter and third quarter, and the phases in between. The new moon occurs when the moon is positioned between the earth and the sun. At this time the three objects are in approximate alignment. At full moon the earth, moon, and the sun are in approximate alignment, just as the new moon, but the moon is on the opposite side of the earth, so the sunlit part of the moon is facing us. The shadowed part is entirely hidden from view. The first quarter and third quarter moons (also called half-moons) occur when the moon is at a 90 degree angle with respect to the earth and the sun. This allows us to see exactly half of the moon illuminated and half of the shadowed part of the moon.
Other fun moon facts: After a new moon and the sunlit portion is increasing, but less than half this is called waxing crescent. After the first quarter the sunlit portion is still increasing, but now more than half this is called waxing gibbous. After the full moon light is decreasing, so this is called waning gibbous. Following the third quarter this is known as waning crescent. And then the cycle begins again!
Moon's Orbit: You may think it takes about one month for the phases of the moon to take place, but actually, it is exactly 29.5305882 days This is the time required for the moon to move to the same position as seen by an observer on earth. If you were to view the moon from outside our solar system (for example from the stars) the time required would be 27.3217 days roughly 2 days less. If you find this interesting then try to figure out why this is?
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