"Chang'e" moon on the back to see what?.

<P> Side of the moon to show people why it always? .</ P> <P> Moon is Earth's only natural satellite, it is endless swing around the Earth. .Since its birth more than four billion years, never left Earth, the planet's most faithful companion. .</ P> <P> look closely, we naturally will have noticed that the side of the moon always show people. .Why is this? .</ P> <P> </ P> <P> moon called the moon. .Dongsheng moon goes down every movement is a reflection of the Earth's rotation. .The performance of the moon rotate around the Earth Star as it moves from west to east, the track is called "White Road." .White Road and the ecliptic (Earth's trajectory around the sun) between the angle between 5 ° and more. .The moon around the earth last week, 27 days 7:43 11.47 seconds, the cycle is called "sidereal month." .In addition to the revolution around the earth, the moon itself is still in rotation. .The moon's rotation period is 27 days 7 hours 43 minutes 11.5 seconds, almost equal to its period of revolution around the earth. .Therefore, at no time, we can only see from the earth forever side of the moon, always back the other side of the earth, "still holds partly concealed." .As the moon's orbit is inclined elliptical orbit, its orbital position at a different side of the Earth for a slightly different, so people can be observed from Earth to the Moon 59% of the entire surface. .</ P> <P> side of the moon always facing the Earth, if without thinking may be that there is no rotation of the moon. .It is not. .We can imagine a point on the surface perpendicular to assume that there is a marker of the lunar surface, and if there is no rotation of the moon, the moon orbiting the earth in the process, as the marker always points to the space in the same direction, so that we observed .The marker point will change, followed by chapters on side towards the Earth's ministries, we should be able to see the back of the moon. .Therefore, only the rotation and the moon around the earth rotation period equal to the same direction (both anti-clockwise direction) the situation, always with the same side to the moon toward the earth. .</ P> <P> the moon's rotation period and the same period of rotation around the Earth, not coincidence, but because between the Earth-Moon tidal gravitational effect. .Lunar tides on the Earth can produce gravity, it can cause water to rise up on both sides of the earth, the atmosphere of the Earth's atmosphere will produce tide. .Similarly, the Earth can also produce gravitational tides of the moon. .The moon's rotation rate over the past much faster than now, when it exists, such as surface lava flows like fluid. .Strong tidal forces from the earth on the moon caused the tides, and tidal friction causes the moon's rotation slows down, until the rotation period equal to the orbital period. .At this point, the Earth was no longer on the moon caused the tides, the moon will be only with the same side towards us. .</ P> <P> tidal friction is not only slow down the rotation of the earth, but also affect the evolution of the Earth-Moon system. .Now, the Earth's rotation period of revolution than the moon's cycle is much shorter, tidal effects will cause deformation of the Earth, mass distribution changes, so that the lunar motion acceleration. .Once accelerated, it will gradually spiral away from Earth orbit into the growing, and thus the Moon around the Earth to the cycle will be longer. .</ P> <P> Moon is currently at an annual rate of 3.8 cm to leave the Earth. .Similarly, tidal friction causes the Earth's rotation has slowed down gradually longer rotation period. .Rotation of the Earth every hundred years an increase of about 0.00164 seconds period, the number small, but should not be underestimated, because the accumulation of considerable long-term. .Maybe about 50 million years to 100 million years, the Earth will one day equal to one month, roughly equal to the current 43 days, when the Earth will also be with the same side toward the moon. .True to that time, the back half moon to full moon on the earth's inhabitants must travel long distances Caixing. .As to which hemisphere had the honor to the moon, it is now uncertain. .</ P> <P> the moon on the back of the first pictures of human </ P> <P> </ P> <P> on earth, one can only vaguely identify with the naked eye on the moon on a dark and bright on the sea .Lu. .With ground-based telescopes, we always only see the front of the moon on the back of the morphology is still unknown. .The fifties of last century, humanity has entered the space age. .Though a number of launches spacecraft on the moon for photography and research, and achieve long-cherished wish of human landing on the moon, the moon so that people began to have a more comprehensive and detailed understanding. .</ P> <P> 1959 年 1 2 March, the former Soviet Union, "Moon No. 1" satellite launch toward the moon, though failed, but played the march of mankind to the moon, exploration and development and utilization of the Moon Overture. .4 October the same year, the Soviet Union has launched the "Moon 3" spacecraft successfully photographed the far side of human history with a picture of the first people to see the back of the style of the moon, the moon began to be exposed in mystery .open. .</ P> <P> "Chang'e" to see the moon on the back </ P> <P> 2007 年 10 月 24 日 18 时 05 hours, China's first lunar probe satellite "Chang'e I" vacated from the Xichang Satellite Launch Center .since, after nearly 20 days after the flight, on November 7 work accurately entered lunar orbit. .November 26, "China's first lunar exploration project first piece of lunar surface images" published. .December 11, "Chang'e I" satellite equipped with CCD camera on the back of the imaging probe the moon and the moon on the back part of the area to get the image data. .The moon on the back part of the regional image data is of great significance, including the moon on the back of a typical radiation impact craters and the "million" impact crater. .This also shows that "Chang'e I" satellite flight, payload management, ground control and communications, data reception and processing, everything working. .</ P> <P> "Chang'e I" for the data, once again that the human had a basic understanding of the moon on the back. .The front side of the moon and the landscape in the main difference is that on the mainland side of the moon (also known as Highland) wide distribution area, the lack of large mare basins, only three small monthly sea (East China Sea, the sea and the Chilean sea in Moscow) is located in the Moon .on the back, and 90% of the moon on the sea front of the distribution. .May the sea than on land because of age to old age, the impact on land surface, the density of pits formed on the sea than on larger, so the hole on the back of the Moon more. .Positive on the moon around the many mountains surrounding kelp, such as the Alps, Apennines, etc., but almost no significant side of the moon mountains. .</ P> <P> the moon's significant difference between the front and back, and the moon's origin and evolution of related. .One hypothesis is that: after the formation of the moon approaching its orbit to Earth, about 3.9 billion years ago, when the moon to run near the Earth's Roche limit, as the Earth-Moon tidal forces of the interaction between the Earth and the Moon positive tear out .part and grinding, and even evaporation, melting, a large number of torn pieces and return to the moon and positive impact on the table, cut a large area on the sea basin, the impact event is called "Rain Sea incident." .The side of the Moon by the Earth-Moon tidal forces have little effect, with no similar Imbrium impact events, thereby maintaining the characteristics of more primitive appearance of months. .</ P> <P> </ P> </ p>.