Why is the moon shining?

Back in those distant times, when the human ancestors only made their first meaningful steps around the planet, the attention of many was lured by the Moon. Why? It's simple! Parents know that even the smallest child who walks with difficulty, seeing the moon in the sky, will pay attention to her adults. Indeed, the bright ball hanging in the night sky, tens of times larger than the largest star, can not remain unnoticed. Every adult knows well why the moon is shining. This is not only obvious, but also explained in the lessons of astronomy.

However, earlier everything was far from obvious and there were many different points of view. For example, early Christians never raised the question of "why the moon is shining." Even on the first pages of the Bible it is said that God created the Sun to illuminate the day (the daylight), and the Moon - to disperse the night darkness (the night star). A little earlier, in the pre-Christian period, the Gentiles considered the Earth satellite to be the goddess-patroness of the night. And even now in literature one can sometimes read about the ghostly moonlight. It is peculiar for a person to believe in miracles ... What is his reason, since it differs so much from the usual sunny or artificial for us? Why does the moon shine? Where, in general, did the epithet "phantom" come from? In fact, the answer to the question "why the moon is shining" is very simple. As is known, any body whose reflection coefficient differs from zero in the larger direction can reflect a part of the light flux incident on it. This property is used by some manufacturers of lighting equipment: there are varieties of chandeliers, the glow of lamps which is directed by reflectors not downwards, as in the usual constructive decisions, but upwards, to the ceiling. Thanks to this, a soft (ghostly) light is created in the room, absolutely not blinding - the so-called diffused light, reflected by the surface of the ceiling in all directions.

Moonlight appears on a similar principle. In our star system, only one celestial body is characterized by intense luminescence - the Sun. Its light flux also falls on the moon, from which it is partially reflected. According to rough estimates, the brightness of the moonlight is sunny by a factor of 26. If our satellite is an absolutely black body, then it could be "seen" only with the help of instruments; Well, have the Moon 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 location of the "Sun-Moon-Earth" conditional system, the visible shape of the Moon periodically changes in the sky. If the satellite falls into the earth's shadow, the sun's rays do not reach its surface, so the night sky is empty (in fact, the Moon is always, just the reflected light of the Earth itself and the stars are not enough to see the satellite). This is the new moon.

The appearance of a luminous sickle symbolizes a new phase - neomenia. A few days later, the right half is already "shining" - 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 shining. Gradually, half turns into a sickle (the letter "C") and the cycle repeats.

Although, it would seem, the natural satellite of our planet should have been fully studied long ago, but it is not so. The exploration of the moon continues. With surprising constancy, the hypothesis is advanced that the satellite is hollow. Indirectly, this is confirmed by inexplicable phenomena, now and then fixed over a surface covered with a layer of dust. Perhaps, inside the Moon there are hidden bases of an unknown race, hidden from a curious human sight. The scientists still have to understand this. Anyway, almost every night we can admire the wonderful moonlight, diligently dispersing the night mist.