People look up at the moon at night and find it always changing? Sometimes rounded like big pies, sometimes turned into bending “brows”, and sometimes there was only a little light. This change, we call it "the cloud of the moon." let's talk today. Why is this moon changing? What's the secret behind it
Let's start with the most important thing: the moon doesn't glow itself! It's bright because it reflects the light of the sun. Imagine the sun being like a big light bulb, the moon is a sphere lit by light, and we stand on earth and look at it. As the moon revolves around the earth, the part of it that is lit by the sun is also changing。
It takes about 27. 3 days for the moon to circle around the earth, but the cycle from a new month to the next new month (which we call the “sweet moon”) is about 29. 5 days. This time difference is due to the fact that the earth and the moon are orbiting around the sun, which takes a little longer to return to its relative position with the earth。
And how does the "black cloud" of the moon change? Let's say in several stages:
The new moon: between the earth and the sun, the back of the sun towards us, so we can hardly see the moon, and the moon is “disappeared”. The month in question (singing): the moon revolves around the side of the earth, and we begin to see it lighted half as if it were half a month. Full moon (round): on the other side of the earth, the sun shines on the side we see, and the moon becomes big and round. The next chord (deficit): the moon continues to turn, and the light is reduced to half a month, but this time it is the other side。
There are many months between these four phases, such as the “brow moon” and the “mutal moon”. The shape of the moon every night is a point on this trajectory of change。
You might ask, why does the moon look like a brow or a cookie shape? This is because we see a part of the sphere lighted by the sun, with shadows and bright borders in different shapes. Like a flashlight to a sphere, the boundaries of light and shadow change with an angle。
This cloudy change not only makes our night sky more beautiful but also affects human life. China’s agricultural calendar is based on the moon’s cycle, and many traditional festivals are related to changes in the moon, such as the mid-autumn festival, which is celebrated on the full moon。
To sum up, the absence of a cloud of the moon is in fact the result of changes in the angle of solar light when the moon turns around the earth. It shows us that the moon's “face” is different every day, and it gives us a sense of the passage of time and the wonder of the universe。
Next night, when you see the moon, don't forget the story behind it. Feel this wonderful gift from the universe
