Even in those distant times, when the ancestors of man only made their first meaningful steps on the planet, the moon attracted the attention of many. Why? Everything is simple! Parents know that even the smallest child, who walks with difficulty when he sees the moon in the sky, will draw the attention of adults to it. Indeed, a bright ball hanging in the night sky, tens of times larger than the largest star, cannot go unnoticed. Every adult knows well why the moon is shining. This is not only obvious, but also explained in the lessons of astronomy.
However, before everything was far from so obvious and there were many different points of view. For example, the early Christians never had the question "why does the moon shine." The first pages of the Bible say that God created the Sun to illuminate the day (daylight), and the Moon - to dispel night darkness (nightlight). A little earlier, in the pre-Christian period, pagans considered the satellite of the Earth the goddess-patroness of the night. Yes, and now in the literature you can sometimes read about the ghostly moonlight. It is human nature to believe in miracles ... What is his reason, since he is so different from the usual solar or artificial? Why is the moon shining? Where did the epithet “ghostly” come from? In fact, the answer to the question “why does the moon shine” is very simple. As you know, any body whose reflection coefficient differs from zero to a larger side is able to reflect part of the light flux incident on it. This property is used by some manufacturers of lighting fixtures: there are varieties of chandeliers, the luminescence of lamps of which is directed by the reflectors not down, as in the usual design decisions, but up, to the ceiling. Thanks to this, soft (ghostly) lighting is created in the room, which is absolutely not dazzling - the so-called diffused light reflected on the ceiling surface in all directions.
Moonlight arises according to a similar principle. In our stellar system, only one celestial body is characterized by intense luminosity - the Sun. Its luminous flux also hits the moon, from where it is partially reflected. According to rough estimates, the brightness of moonlight is 26 times less than that of the sun. If our satellite was a completely black body, then it could be "seen" only with the help of instruments; Well, if the Moon had a mirror surface, then its luminosity would almost not be inferior to the Sun.
There are phases: a new moon, a young moon, a quarter, a full moon. Since the shape of the satellite is spherical, depending on the relative position of the conventional Sun-Moon-Earth system, the visible shape of the Moon in the sky periodically changes. If the satellite falls into the earth’s shadow, then the sun’s rays do not reach its surface, so the night sky is empty (in fact the moon is always there, just the reflected light of the Earth itself and the stars are not enough to see the satellite). This is a new moon.
The appearance of a luminous sickle symbolizes a new phase - non-mania. After a few days, the right half is already “lit up” - this is the first quarter. Then comes the time of the full disk - the full moon. And finally, it is replaced by the last quarter - the left half is lit. Gradually, half turns into a sickle (letter “C”) and the cycle repeats.
Although, it would seem, the natural satellite of our planet should have been fully studied for a long time, but this is not so. Moon exploration is ongoing. With surprising consistency, assumptions are made that the satellite is hollow. Indirectly, this is confirmed by inexplicable phenomena, which are now and then fixed over a surface covered with a layer of dust. Perhaps inside the moon there are secret bases of an unknown race, hidden from a curious human gaze. This remains to be understood by scientists. Be that as it may, almost every night we can admire the wonderful moonlight, carefully dispersing the darkness of the night.