Why can I see the moon at three o'clock in the afternoon?

First of all, seeing the moon requires a condition that the moon is above the horizon. This may sound like some nonsense, but it is a very important prerequisite. Today's moon phase is about the ninth day of the ninth lunar month, so at 3 pm, the moon has already risen, which meets this condition.

There are so many stars in the sky during the day, why can't you see them? Obviously, it is not enough to meet the above conditions, but also to meet the second condition. The limit magnitude of the sky is greater than the brightness of the observed celestial body. Let me talk about what is the limit magnitude, that is, the brightness of the darkest celestial body that can be seen during observation. The above sentence is popular, that is, the observed object is brighter than the limit brightness of the sky, which sounds like another nonsense.

Today, the landlord saw the moon at three o'clock in the afternoon, which also shows that the landlord has met the second condition I just said. The brightness of the moon is greater than the limit magnitude of the observation point. Why is this happening?

First, at three o'clock in the afternoon, the sun has set in the west, the strong scattering of sunlight in the atmosphere is not as strong as that at noon, and the limit in the sky is slowly decreasing (that is, the brightness of observable celestial bodies is slowly rising).

Second, today is the ninth day of the ninth lunar month, and the moon has passed the first quarter. Most of the moon is bright, so the brightness is relatively high, which can reach about-12. 、

Third, the moon on the ninth day of the ninth lunar month is far from the sun, about 120. At such a long distance, the influence of sunlight has been greatly reduced, so the limit magnitude is relatively low far from the sun, and celestial bodies are easy to observe.

Fourth, the air quality at the observation point where the landlord is located is good (at least today). If there is a lot of dust in it, it will lead to strong scattering of sunlight and affect the limit magnitude of the sky. I saw the moon at 2 pm on the fourth day of the fourth lunar month (the height of the sun is higher than that of the landlord, the brightness of the moon is lower than today, and the distance between them is shorter than today). National Solar Observation Base, of course.

Said a lot, but also a little messy. I wonder if it will help the landlord. If you have any questions, please exchange and discuss.