The moon the satellite of the Earth
Luna (lat. Luna) – Earth’s natural satellite. The closest planet to the Sun, the satellite, as the closest planet to the Sun, Mercury and Venus, satellites do not. The second yarkostiobekt on the terrestrial sky after the Sun and the fifth largest natural satellite of a planet of the Solar System. The average distance between the centers of the Earth and the Moon – 384,467 km (0,002 and 57. E., About 30 Earths). The apparent magnitude of the full Moon in Earth’s sky -12,71m.Osveschёnnost created a full moon near the Earth’s surface in clear weather, 0.25 – 1 lux. The moon is the only astronomical object beyond Earth where people visited.
The word goes back to the moon praslav.The word goes back to the moon praslav. * luna Luna Orbit Since ancient times people have tried to describe and explain the motion of the moon. Over time there were more and more accurate theory. The basis for calculation is the modern theory of Brown. Built at the turn of XIX-XX centuries, it describes the motion of the moon with a precision measuring instruments of the time. In the calculation used by more than 1,400 members (coefficients and arguments in the trigonometric functions). Modern science can count the movement of the moon and check these calculations with greater accuracy. The methods of laser ranging measured distance to the moon with an error of a few centimeters . Such accuracy has not only measure, but also the theoretical predictions of the position of the moon; for these calculations used the expression with tens of thousands of members and there is no limit to their number if you need even more high precision. As a first approximation we can assume that the Moon moves in an elliptical orbit with an eccentricity of 0.0549 and the major axis 384 399 km. The actual motion of the moon rather complicated, when the calculation should take into account many factors, such as flattening of the Earth and the strong influence of the Sun, which attracts the moon is 2.2 times stronger than Zemlya.Bolee exact movement of the Moon around the Earth can be viewed as a combination of several movements: rotation around the Earth in an elliptical orbit with a period of 27.32166 days, the so-called sidereal month (that is, the movement is measured relative to the stars); rotation of the plane of the lunar orbit: its components (the point of intersection of the orbit to the ecliptic) are shifted to the west, making a complete revolution in 18.6 years. This motion is precession; the rotation of the major axis of the lunar orbit (apsidal line) with a period of 8.8 years (going in the opposite direction than the above mentioned movement of nodes, that is, the longitude of the perigee increases); periodic variation of the inclination of the lunar orbit to the ecliptic from 4 ° 59 ‘and 5 ° 19′; periodic variation in the size of the Moon’s orbit: Perigee from 356.41 to 369.96 thous. km, apogee of 404.18 to 406.74 thous. km; Moon gradual removal from the earth due to tidal acceleration (about 4 cm per year), thus its orbit is slowly unwinding helix.
The general structure
The moon is made of bark, the upper mantle (asthenosphere), middle mantle, lower mantle and core. The atmosphere is almost absent. The surface of the moon is covered by the so-called regolith – a mixture of fine dust and rocky debris produced by collisions of meteorites with the lunar surface. Shock-blasting processes accompanying the meteorite bombardment, promote backwashed and mixing the soil at the same time sintering and compacting the soil particles. The thickness of the regolith is from a meter to tens of meters. The thickness of the crust of the moon varies widely from 0 to 105 km.Po data from satellite gravity exploration GRAIL, the thickness of the lunar crust more on the hemisphere that faces Earth. Conditions on the surface of the moon The atmosphere of the moon is very sparse. When the surface is illuminated by the sun, the content of the gases above it does not exceed 2,0 • 105 particles / cc (for the Earth, the figure is 2,7 • 1019 particles / cc), and after sunrise is increased by two orders of magnitude due to the decontamination of the soil. Rarefied atmosphere leads to a high or low temperature on the surface of the moon (from -160 ° C to +120 ° C) [source Unknown 1187 days], depending on the light; wherein the temperature of the rock at the depth of 1 m, is constant and is equal to -35 ° C. In view of the practical lack of atmosphere, the sky is always black on the moon, with the stars, even when the sun is above the horizon. Earth disc of the moon hanging in the sky almost motionless. Reasons small monthly fluctuations earth height above the lunar horizon and azimuth (about 7 °) are the same as in the libration. The angular size of the Earth as seen from the moon is 3.7 times larger than the Moon as seen from Earth, the Earth and the closing area of the celestial sphere at 13.5 times larger than the Moon closable. The degree of illumination of the Earth as seen from the moon, the lunar phase reverse, visible on Earth during a full moon the moon is visible c unlit part of the Earth, and vice versa. Lighting reflected light of the Earth about 50 times stronger than the moonlit in the world, the maximum apparent magnitude of the Earth to the Moon is about -16m. source: wikipedia