|The hidden face of the moon|
On January 2, a Chinese spacecraft landed on the opposite side of the moon.
The fact that the moon rotates around its axis in the same time that it revolves in an elliptical orbit around the Earth has the consequence that our satellite always shows us the same face. For several centuries, the hidden face of the moon was an enigma. In 1870, the science-fiction novel Around the Moon, by Jules Verne, leaves open the possibility that in the hidden face of the moon there could be air, water, life, and even intelligent inhabitants. While the three travelers pass over the hidden face during the lunar night, unable to see anything on the surface, a sudden flash of light caused by a meteor shower illuminates for a moment the hidden area and shows them clouds, seas, forests... or at least that’s what the dazzled observers think they have seen.Actually, we can see directly a little more than half the surface of the moon. While revolving around the Earth, the moon wobbles slightly (libration), and sometimes shows a small part of the hidden face at one edge, sometimes at the other. Thus we can see, at one time or another, 18% of the hidden face, while the other 82% always remains out of sight. In other words: we see 59% of the total area of the moon, while 41% is always hidden from us.
The first unmanned spacecraft that circumnavigated the moon and could see the opposite side was the Soviet capsule Luna 3, which on October 7, 1959 took the first photographs, which allowed the USSR Academy of Sciences to publish one year later the first atlas of the opposite side of the moon. Later, in 1965, another unmanned Soviet capsule, Zond 3, again circumnavigated the moon and obtained photographs with higher resolution. It was discovered that the hidden face is riddled with craters, but lacks "maria" (lava plains) like those dotting the visible face of the moon.
The first time human beings saw directly the hidden face was in December 1968, when the three astronauts of Apollo 8 circumnavigated several times the moon. Other astronauts from the successive missions of the Apollo project, which put the first man on the moon (Apollo 11, July 20, 1969), could also see the hidden face while circumnavigating the moon.
|First photograph of the hidden face|
The Chinese space probe (Chang'e 4, whose name refers to the Chinese goddess of the moon) is the first in history to have landed on the opposite side, in the Aitken basin, near the South Pole, one of the largest impact areas of the solar system, inside the Von Kármán crater, 186 kilometers in diameter. This is an unmanned ship, in the style of NASA’s Mars missions, equipped with a robot vehicle, Yutu 2 (Jade Rabbit 2), which will explore the crater.
The Chinese lunar program began in 2007 with the space probe Chang'e 1, which for a year and a half flew around the moon, until it crashed into it in 2009. The first controlled Chinese moon landing was performed by the Chang'e 3 probe on December 14, 2013. It was the first time a probe from the Earth had landed on the moon since August 1976, when the Soviet capsule Luna 24, managed to return to Earth with lunar samples.
What will the Chinese probe do, that has landed for the first time on the opposite side?
1. It will take the first photographs at ground level of the lunar landscape of the hidden side.
2. It will measure the composition of the ground, just below the capsule.
3. It will measure the radiation coming from space, to estimate the survival possibilities of human beings in this hostile environment.
4. It will check whether it is possible to breed plants and small animals (insects) in controlled environments on the moon. One of these experiments has now been performed.
5. It will be the basis for the next mission, scheduled for 2019, which will try to return to Earth with samples of the ground of the hidden face of the moon.
As for future manned missions to the moon, China plans to do it by 2036, and North Korea has announced intentions in that regard, although it will not be soon. As for NASA, it has plans and budgets to launch an unmanned lunar probe in 2022, but there is no date for a new manned attempt, as this would depend on the result of the previous one.
The same post in Spanish
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