Group V Phases Of The Moon
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The phases of the moon are when you can only see part of the moon because only part of it is illuminated. The moon is illuminated because it reflects the light from the sun. The part of the moon facing the sun is lit up. The part facing away from the sun is in darkness. Exactly half of the moon is always illuminated, but not always facing directly towards the earth, therefore we can only different parts of the moon lit up at different times. Countries near the equator see the crescent moon shaped like a smile. The phases of the moon work in a cycle starting with the new moon. A complete cycle of the Moon's phases from new Moon to full Moon takes twenty nine and a half days.

In Western culture, the four principal lunar phases are new moon, first quarter, full moon, and third quarter (also known as last quarter). During the time between principal phases, the Moon appears or gibbous (more commonly know as crescent). These shapes, and the periods of time when the Moon shows them, are called the intermediate phases. They last, on average, one-quarter of a synodic month, roughly 7.38 days, but their durations vary slightly because the Moon's orbit is slightly elliptical, and therefore its speed in orbit is not constant. The descriptor waxing is used for an intermediate phase when the Moon's apparent size is increasing, from new moon toward full moon, and waning when the size is decreasing.

When the Sun and Moon are aligned on the same side of the Earth, the moon is "new", and the side of the Moon facing Earth is not illuminated by the Sun. As the moon waxes (the amount of illuminated surface as seen from Earth is increasing), the lunar phases progress through new moon, crescent moon, first-quarter moon, gibbous moon, and full moon. The moon is then said to wane as it passes through the gibbous moon, third-quarter moon, crescent moon and back to new moon.The terms "old moon" and "new moon" are not interchangeable. The "old moon" is a waning sliver (which eventually becomes undetectable to the naked eye) until the moment it aligns with the sun and begins to wax, at which point it becomes new again.

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