The moon is the earth's natural satellite. It consists of a rocky body 3 476 km in diameter, almost a third the size of the earth. The average distance from Earth to the Moon is 384 400 km.
Our satellite has no atmosphere to protect humans or other living beings from direct exposure to solar radiation, such as ultraviolet radiation.
There is neither water nor volcanoes because, unlike Earth, the Moon has the innermost solid state (no magma). But there are many craters, usually formed by the impact of celestial bodies in the past. The collisions melted rocks and formed lava, which cools and appears as dark areas on the moon called seas.
The temperature on its surface varies, on average, from 100ºC to -150ºC. All these conditions do not allow the existence of living beings on the moon. The Earth observer perceives the apparent movement of the moon and the other visible stars in the night sky east to west.
The main movements of the moon are: translation around the earth it's from rotation about its own axis. These two movements are about the same duration: approximately 27 days and 8 hours. For this reason, the moon always keeps the same face facing the earth.
The phases of the moon
The glow of the moon is a reflection of sunlight. Like planets, she has no light of her own. The earthly observer sees different parts of the moon illuminated by the sun as it moves around the earth. These different aspects, called phases of the Moon, are: New Moon, Crescent, Full Moon and Waning.bedroom: means 1/4. The sun illuminates half of the lunar sphere, and from here on earth we see only half of the sunlit portion, that is, 1/4 of the moon.
The New Moon phase is when your illuminated face is opposite the Earth. We are facing the unenlightened face. At this stage the moon is not seen in the night sky.
In the following days, the moon has the appearance of an illuminated bow and can sometimes be seen in the evening.
As the moon moves around the earth the part we see illuminated increases. After about seven days she is in her phase First Quarter.
The moon follows its orbit. Each day increases its illuminated region seen from Earth. When the moon is opposite the position of the sun relative to the earth, the moon faces us completely illuminated. is the phase of Full moon. At this time the moon rises in the sky in the early evening.
In the following nights, we can observe that the illuminated part of the moon begins to diminish until only half of its face is seen. It looks in the sky well into the night and can be seen at dawn. it's the phase Waning Room.
The moon moves in its translation, changing its position in relation to the earth and the sun. For those who observe it from the earth, the illuminated part diminishes until it is not seen in the sky again. The moon then completes its cycle and returns to the phase of New Moon.
The four phases of the moon take place in continuous cycles over a period of 29 days and 12 hours.