The Moon's Importance
The Moon's Role
Have you ever wondered why sometimes the moon looks like it's just a little sliver in the sky, when other times it's completely round? Or why does a sandcastle get washed away after just a small while? What if you looked up in the night sky and saw a dim red ball where the moon is supposed to be? These all have to do with the moon, its movements, and its forces on Earth.
Some nights, the moon looks like a tiny silver curve in the night sky. Some nights you can't see it at all. Some nights it's obviously present, a completely illuminated circle among the stars. Why is this? It all has to do with the movements of both the Earth and the moon. As the moon revolves around Earth, the sun's rays always light one half of the moon. But depending on where the moon is in its orbit, we might not be able to see the completely illuminated half. When we see none of the illuminated side, the phase is called a new moon. After that, the moon gets slightly smaller each night, causing waxing crescent, first quarter (half moon), and waxing gibbous. Then, there's full moon, where we can see the entire lit side of the moon. After that follows waning gibbous, third quarter (another half moon), and waning crescent. Then you're back to seeing none of the lit side, or the new moon phase. Going from new moon to new moon takes between 27 and 29 days, giving us about a month.
Tides occur when the moon's gravitational force pulls the water on Earth's surface towards it. This is what causes the water to move closer and farther up the shore, and also what causes sandcastles to be washed away. If you build the castle on a low tide, then when the water rises for a high tide, it will be destroyed. But how do tides work? As the Earth rotates, the moon is near a different part at different times. The moon's gravity pulls the water towards itself, causing a high tide in that area and low tides on the northernmost and southernmost parts of the Earth. However, there's a high tide on the opposite side of the Earth at the same time. This is because the moon's gravity isn't strong enough to pull the entire ocean to one side. The water gathers on the opposite sides of the Earth. This causes two low tides and two high tides at any given time on Earth.
There are two main types of eclipses: lunar and solar. Solar eclipses have two kinds, like lunar. The two kinds of solar eclipses are annular and total. An annular is when the moon and sun don't quite line up, so only part of the sun is blocked out. A total is when the moon and sun line up perfectly, and the only part of the sun you can see is its outer atmosphere-its corona. The two kinds of lunar eclipses are partial and total. Partial lunar eclipses occur when the moon goes into the Earth's penumbra, and partially into the umbra, but not completely. A part of the moon is turned completely dark. A total lunar eclipse happens when the moon passes completely into Earth's umbra. The moon appears red in the night sky.
Life on Earth without the moon would be very different. Tides wouldn't occur, there would be no basis for a lunar calendar, eclipses would never occur, and the Earth would wobble as it rotates, because of the moon keeping the Earth's axis stable. The moon plays an important role, and we take it for granted. It has provided a basis of time, movement of water, a steady rotation, and phenomena that we consider ourselves lucky to see.