China says it successfully landed a spaceship on the other side of the Moon, the first such attempt and landing.
She carries instruments to analyze the geology of the unexplored region and perform biological experiments.
The landing is considered an important milestone in space exploration.
There have been numerous missions to the moon in recent years, but the vast majority were in orbit, by-pass or by-pass. The last manned landing was Apollo 17 in 1972.
The Chang & # 39; e-4 probe has already returned first images shared by state media of the surface.
Since no direct communication link is possible, all images and data must be bounced off a separate satellite
Why is this moon landing so important?
Earlier lunar missions have landed on the near-Earth side, but this is the first time a vehicle has landed on the unexplored and rugged backcountry.
Ye Quanzhi, an astronomer from Caltech, told the BBC that this was the first time China had "tried something that other space powers had not tried before."
The Chang & # 39; e-4 was launched by the Xichang Satellite Launch Center in China on December 7; She arrived in Lunar Orbit on December 12th.
The Chang & # 39; e-4 probe intends to explore a site called "Von Kármán", which is located in the much larger South Pol Aitken Basin (SPA). It is believed to have been caused by a huge impact at the beginning of the lunar history
"This huge structure is over 2,500 km in diameter and 13 km deep, one of the largest impact craters of the solar system and the largest, deepest and oldest basin on the moon, "said Andrew Coates, professor of physics at the Mullard Space Science Laboratory of UCL in Surrey told the BBC.
The event responsible for cutting out the SPA Basin is considered so powerful that it moved through the lunar crust into the zone called the Mantle. Researchers will want to train the instruments on each mantle rock exposed by the disaster.
The science team also hopes to study parts of the molten rock that filled the newly formed South Pole Aitken Basin to recognize variations in its composition.
A third goal is the exploration of the distant Side Regolith, the fragmented rocks and the dust that form the surface will help us to understand the formation of the Moon.
What else can we learn from this mission?
The static lander of Chang & # 39; e-4 wears two cameras; a radiation experiment built in Germany called LND; and a spectrometer that will perform low frequency radio astronomy observations.
Scientists believe that the other side could be an excellent place for radio astronomy because it is shielded from the radio noise of the earth. The spectrometer work should test this idea.
The lander owns a 3 kg container containing potato seeds and Arabidopsis plant seeds and silkworm eggs to conduct biological studies. The Moon Minibiosphere experiment was designed by 28 Chinese universities.
Other devices / experiments include:
- A panoramic camera
- A radar for investigation under the lunar surface
- An imaging spectrometer for the identification of minerals  Experiment for studying the interaction of the solar wind (a stream of high-energy particles the Sun) with the Moon's Surface
The mission is part of a larger Chinese lunar research program. The first and second Chang'e missions were designed to collect data from orbit, while the third and fourth were built for surface operations.
Chang & # 39; s-5 and 6 are pattern return missions that deliver lunar rocks and soil to laboratories on Earth.
Is there a "dark side of the moon"?
The lunar side is often referred to as the "dark side," although "dark" in this case means "unseen" and not "without light." In fact, both the near and the far side of the moon experience day and night.
However, due to a phenomenon known as "taming," we only see one side of the moon from Earth. This is because the moon takes just as long to spin around its own axis as it takes to complete Earth's orbit. There are also very few "mares" – dark basaltic "seas" created by lava flows – visible on the near side.
How will scientists track the Rover?
In an article for the US, Long Xiao of the Chinese University of Earth Sciences (Wuhan) said in September, "The challenge of a long-distance mission is communication." "There is no way to establish a direct radio link without seeing the Earth
Landers must communicate with Earth via a relay satellite called Queqiao – or Elster Bridge – which China launched last May.
Queqiao orbits 65,000 km behind the Moon around a Lagrange point – a kind of gravity parking spot in space, where it remains visible to ground stations in China and other countries such as Argentina.
Is it all about science?
No. The landing is an important step in China's aspiration to become a leader next to the United States and Russia Power to become in space research.
The BBC's John Sudworth in Beijing says the propaganda value of a jump in China's space ambi It was underlined by careful media management – with very little news about the landing trial before the official announcement that it had been a success.
But Fred Watson, who aspires to Australia's astronomy as his astronomer, says secrecy could be as simple as caution, much like the Soviet Union did in the early days of its rivalry with NASA.
"The Chinese Space Agency is a young organization, but maybe it will catch up in the coming years," he told the BBC.
Ye Quanzhi says China has been trying to be more open.
"They beamed the launch of Chang's 2 and 3 as well as the landing of Chang's 3-PR skills out of time to develop, but I think China will get th," he said.
China is a belated starter when it comes to space exploration. "It was not until 2003 that it sent its first astronaut into orbit, making it the third country after the Soviet Union and the US.
The landing on the landing has already been announced by NASA experts as "first humanity" and an impressive achievement ".