The natural and only satellite of the Earth, the Moon, after the Sun is the second object in brightness. In magnitude, it is the fifth object of the solar system. Between the centers of the Moon and the Earth, the average distance is 384,467 km. The mass of the moon corresponds to a value of 7.33 * 1022kg.
Since ancient times, people have attempted to describe and explain its movement. The basis of all modern calculations is Brown's theory, which was created at the turn of the XIX - XX centuries. To determine the exact motion of this celestial body, it was necessary not only the mass of the moon. Numerous trigonometric function coefficients were taken into account. Modern science can make more accurate calculations.
Laser location allows you to measure the size of celestial objects with an error of only a few centimeters. With its help, it was found that the mass of the moon is much less than the mass of our planet (81 times), and its radius is 37 times less. For a long time it was not possible to accurately determine this value, but the launch of space satellites allowed us to open new perspectives. An interesting fact is known that in Newton's time the mass of the moon was determined by the magnitude of the tide it caused.
We can see the illuminated surface of this satellite in different ways. The visible part of the disk illuminated by the Sun is called the phase. There are four phases in total: the completely dark surface of the moon - the new moon, the growing lunar crescent - the first quarter, the fully illuminated disk - the full moon, the illuminated half on the second side - the last quarter. They are expressed in hundredths and tenths of a unit. The change of all lunar phases is a synodic period, which is the revolution of the moon from the phase of the new moon to the subsequent new moon. It is also called the synodic month, equal to approximately 29.5 days. During this period of time, the Moon will be able to go in orbit and have time to visit the same phase twice. The sidereal period of revolution, lasting 27.3 days, is the full revolution of the moon around the earth.
The assertion that the surface of the moon we see on one side and that it does not rotate is erroneously widespread. The movements of the moon occur in the form of rotation around its axis and revolution around the earth and the sun
A complete revolution around its own axis occurs in 27 Earth days 43 min. and 7 hours. The revolution in an elliptical orbit around the Earth (one full revolution) occurs in the same time. This is influenced by the tides in the lunar crust, causing tides on Earth, occurring under the influence of lunar attraction.
Being at a farther distance from the Moon than the Earth, the Sun, because of its huge mass, attracts the Moon twice as much as the Earth. The Earth distorts the trajectory of the moon around the sun. In relation to the Sun, its trajectory is always concave.
The moon has no atmosphere, the sky above it is always black. Due to the fact that sound waves do not propagate in a vacuum, complete silence reigns on this planet. Under direct rays of the sun, the temperature in the daytime is many times higher than the boiling point of water, and at night it reaches -150 C. The specific gravity of the moon is one. Its density is only 3.3 p. more water. On its surface there are huge plains that are covered with frozen lava, many craters formed during the fall of asteroids. The force of gravity is inferior to gravity, and the weight of the moon is less than the earth, so the weight of a person’s body can decrease by 6 times when on the moon.
According to radioactive substances, scientists have determined the approximate age of the moon, which is 4.65 billion years. According to the latest most plausible hypothesis, it is assumed that the formation of the moon occurred as a result of a giant collision with a young Earth of a huge celestial body. According to another theory, the Earth and the Moon were independently formed in completely different parts of the solar system.