Science Common Sense
586 - What are the different phases of the moon, and how do they occur?
Imagine you have a big flashlight, the sun, and a ball, the moon. The Earth is in the middle. The moon goes around the Earth in about 28 days. As it moves, different amounts of sunlight shine on the moon from our point of view on Earth. This makes the moon look different in the sky. Here are the main phases:
- New Moon: The side of the moon facing the Earth is not lit by sunlight.
- Waxing Crescent: A small part of the moon's lit side is facing the Earth and appears to grow.
- First Quarter: Half of the moon's lit side is facing us, like half a circle.
- Waxing Gibbous: The lit side continues to grow, looking bigger and fuller.
- Full Moon: The whole lit side of the moon is facing the Earth, so the entire moon is visible.
- Waning Gibbous: The lit side starts to decrease in appearance, looking smaller and smaller.
- Last Quarter: Half of the moon's lit side is facing the Earth again, but on the opposite side from the First Quarter.
- Waning Crescent: The amount of the moon's lit side visible to us continues to get smaller and smaller.
- Back to New Moon: The side of the moon facing the Earth is not lit by sunlight again, and the cycle starts over.
These phases happen because of the changing angle between the sun's light, the moon, and our point of view on Earth.