The Moon is the earth’s natural satellite and the only astronomical body visited by humans; it is the brightest celestial body in the dark sky; at night, it reflects the light from the sun. The Moon is located at 238,328 miles; 384,400 km. from earth. It has a diameter of 2155.12 miles; 3476 km., and a radius of 1076 miles; 1737.4 km.
Because the Moon is less massive than the earth, the gravitational pull on its surface is 1 / 6 of that on earth. Thus a person on the Moon´s surface would feel as if his weight had decreased by 5 / 6.
Despite the relative gravitational pull of the Moon. This is close enough to produce the ocean tides on Earth. There is no life of any kind on the Moon; the sky is always dark even during the day, and the stars are always visible.
The bright areas are heavily cratered mountains. The ranges are the original crust of the moon, bombed and fragmented ‘by the impact of meteorites, asteroids and comets. Some craters in these mountains exceed 2.5 miles; 4 km. in diameter. The longest is at the South Pole (aitken Basin) and measures 1388 miles; 2500 km. in diameter.
The dark areas on the surface of the Moon are known as Maria. The term is derived from the similarity they have to water bodies that exist on earth. The Marias are cratered lands that were partly flooded by lava when volcanoes erupted. The lava then froze, forming rock, since that time, meteoroid impacts have created craters in the Marias.
As the Moon orbits the earth, an observer on earth can see the Moon changer its form gradually from new Moon to full Moon. The form is different from one day to the next. The moon goes through a complete cycle of phases in a synodic month.
When the Moon is between the Sun and the Earth, its sunlit side is opposition with the Earth. Astronomers call this: “dark face new moon”. On the first night after the full moon, a small portion of the moon is illuminated along the eastern edge of the moon. Each night an observer on Earth can see more of the illuminated area, where the terminator (the line between the illuminated and dark area) move westward.
Just as the Sun, the Moon rises in the east and lies in the west. While the Moon progresses in its faces through the sky, it gets up and hides at different periods of time. When the Moon reaches its new Moon phase, it rises with the sun and travels with the sun in the sky. On each successive day, the Moon rises about 50 minutes later.