China's Chang'e-4 probe makes historic landing on moon's far side
Photo provided by the China National Space Administration on Jan. 3, 2019 shows the first image of the moon's far side taken by China's Chang'e-4 probe. China's Chang'e-4 probe touched down on the far side of the moon Thursday, becoming the first spacecraft soft-landing on the moon's uncharted side never visible from Earth. The probe, comprising a lander and a rover, landed at the preselected landing area at 177.6 degrees east longitude and 45.5 degrees south latitude on the far side of the moon at 10:26 a.m. Beijing Time (0226 GMT), the China National Space Administration announced. (Xinhua)
BEIJING, Jan. 3 (Xinhua) -- China's Chang'e-4 probe touched down on the far side of the moon Thursday, becoming the first spacecraft soft-landing on the moon's uncharted side that is never visible from Earth.
The probe, comprised of a lander and a rover, touched down at the preselected landing area at 177.6 degrees east longitude and 45.5 degrees south latitude on the far side of the moon at 10:26 a.m. (Beijing Time), the China National Space Administration (CNSA) announced.
With the communication assistance of the relay satellite Queqiao, meaning Magpie Bridge, the probe sent back the first-ever close-up photograph of the moon's far side, opening a new chapter in lunar exploration.
After the Beijing Aerospace Control Center sent an order at 10:15 a.m., the Chang'e-4 probe, launched on Dec. 8, 2018, began to descend from 15 km above the moon with a variable thrust engine being ignited, said CNSA.
The Chang'e-4's relative velocity to the moon was lowered from 1.7 km per second to close to zero, and the probe's attitude was adjusted at about 6 to 8 km above the lunar surface.
At 100 meters up, the probe hovered to identify obstacles and measured the slopes on the surface. After avoiding the obstacles, it selected a relatively flat area and descended vertically and slowly.
Then the probe landed in the Von Karman Crater in the South Pole-Aitken Basin.
During the descending process, a camera on the probe took photos of the landing area.
After landing, the solar panels and antennas on the probe were unfolded under the control of the space engineers in Beijing through the communication transmission of the relay satellite, which was operating in the halo orbit around the second Lagrangian (L2) point of the earth-moon system, about 65,000 km from the moon, where it can see both Earth and the moon's far side.
The first close-up photo of the moon's far side, taken by a monitoring camera on the lander at 11:40 a.m., showed the direction the rover would drive on to the lunar surface.
The control center in Beijing will choose a proper time to let the rover separate from the lander, according to CNSA.
The Chang'e-4 probe, carrying eight payloads including two developed through international cooperation, will conduct low-frequency radio astronomical observation, survey the terrain and landforms, detect the mineral composition and shallow lunar surface structure and measure the neutron radiation and neutral atoms to study the environment on the far side of the moon, according to CNSA.
The mission provides the world's scientists more opportunities to explore the universe.
The moon is tidally locked to Earth, rotating at the same rate that it orbits Earth. Therefore, only one side of the moon is seen from Earth, leaving the far side a mystery before the age of spacecraft.
Many lunar orbiters have shown the moon's two sides are very different: the near side has more and relatively flat lunar mares, while the far side is thickly dotted with impact craters of different sizes.
Scientists infer that the lunar crust on the far side is much thicker than the near side. However, the reality is still a mystery, and only in-situ exploration might reveal the secrets.
For astronomers, the far side of the moon is a place of ideal tranquility, as the body of the moon shields against radio interference from Earth. From there, they could study the origins and evolution of stars and galaxies, peering into the dawn of the universe.
Chang'e-4's low-frequency radio astronomical observation on the moon's far side will fill gaps in astronomical observation.
Photo provided by the China National Space Administration on Jan. 3, 2019 shows an image taken by China's Chang'e-4 probe during its landing process. China's Chang'e-4 probe touched down on the far side of the moon Thursday, becoming the first spacecraft soft-landing on the moon's uncharted side never visible from Earth. The probe, comprising a lander and a rover, landed at the preselected landing area on the far side of the moon at 10:26 a.m. Beijing Time (0226 GMT), the China National Space Administration announced. (Xinhua)
Photo provided by the China National Space Administration on Jan. 3, 2019 shows an image taken by China's Chang'e-4 probe after its landing. China's Chang'e-4 probe touched down on the far side of the moon Thursday, becoming the first spacecraft soft-landing on the moon's uncharted side never visible from Earth. The probe, comprising a lander and a rover, landed at the preselected landing area on the far side of the moon at 10:26 a.m. Beijing Time (0226 GMT), the China National Space Administration announced. (Xinhua)
China Focus: Chang'e-4 lands on largest crater in solar system
BEIJING, Jan. 3 (Xinhua) -- China's Chang'e-4 lunar probe has made the first-ever soft landing on the far side of the moon. Experts believe that the precise landing will help prepare the country for its following lunar exploration and future expeditions to other planets.
The probe, comprising a lander and a rover, landed at the preselected landing area at 177.6 degrees east longitude and 45.5 degrees south latitude on the far side of the moon at 10:26 a.m. Beijing Time, the China National Space Administration announced.
The landing area is the Von Karman Crater, named after a Hungarian-American mathematician, aerospace engineer and physicist, within the Aitken Basin. The area was intentionally selected after much consideration.
"When discussing the Chang'e-4 mission, we thought we should attach more creativity and functions to it, enabling it to do more challenging things," said Wu Weiren, chief designer of China's lunar probe program.
The far side of the moon was not the only first at first. Some experts even considered landing on other celestial bodies, but it would have required great changes made for the probe.
As Chang'e-4 began as a backup for Chang'e-3, many of their components and parts were designed and manufactured together, which allowed little room for changes, according to Sun Zezhou, chief designer of the Chang'e-4 probe, from China Academy of Space Technology.
Since the moon's revolution cycle is the same as its rotation cycle, the same side always faces the earth. The other face, most of which cannot be seen from Earth, is called the far side or dark side because most of it is uncharted.
"The rugged terrain of the moon's far side has made the landing much more risky than on its near side. However, more accurate landing technology is needed in the future," Sun said.
"For example, if we want to send detectors to the moon's bumpy polar regions and descend them on a relatively small area with permanent sunshine, it will demand very high landing precision," he explained.
"If we want to build a scientific research station on the moon, we will need to land multiple probes within the same area so that they can be assembled easily into a complex, which requires even greater landing accuracy," he said.
"So solving the challenges of the Chang'e-4 mission can lay the foundation for the following lunar exploration and future landing on other planets," he noted. "We hope that we will have the capacity to get to the whole moon and even the whole solar system in the future to support our deep space scientific explorations."
After the far side of the moon is determined as the destination, the specific landing area is narrowed by various restrictions.
Chang'e-3, launched in 2013, is the first Chinese spacecraft to soft-land on and explore an extraterrestrial object. Its thermal control system and solar wings are designed in line with the sunshine conditions at its landing area, Sinus Iridum or the Bay of Rainbows, at around 45 degrees north latitude. With almost the same design, Chang'e-4 is therefore preferred to land on an area between 40 and 50 degrees in latitude, Sun said.
After deciding the latitude, experts went on to consider the longitude. "To set up the communication link between the earth and the moon's far side, the relay satellite 'Queqiao' was launched in May and is now running on a halo orbit around the second Lagrangian point of the earth-moon system. It could only cover an area between dozens of degrees in longitude away from the central point of the far side for all-time communications," Sun said.
"And we don't want the elevation angle too small in case signals are hindered by surrounding mountains when the probe communicates with the relay satellite," he added.
Within the circled latitude and longitude, scientists pinned their eyes on the Aitken Basin, the largest, deepest and oldest crater in the solar system. It may contain the earliest information about the moon, for example whether it once had water. Exploration in this area will provide firsthand data and clues for the evolution of the moon, earth and solar system.
About 2,500 kilometers in diameter and 13 kilometers in depth, the Aitken Basin has a small crater, Von Karman, inside it. The latter, 180 kilometers in diameter, is relatively flat in its bottom, making it the best choice for landing.
About 13 degrees in longitude away from Von Karman, there is Chretien Crater, a perfect alternative landing area. If Chang'e-4 fails to touch the surface of Von Karman on the first day, it could land on the alternative area on the second day.
Shen Zhenrong, a designer of the Chang'e-4 probe, believes the mission will be a contribution for the whole world. "Although we don't know what Chang'e-4 will discover yet, the exploration is highly possible to influence generations of people."
Breathtaking 12 minutes for Chang'e-4's landing
BEIJING, Jan. 3 (Xinhua) -- Over about 12 dramatic minutes, China's Chang'e-4 probe descended and softly touched down on a crater on the far side of the moon on Thursday.
Wu Weiren, chief designer of China's lunar exploration program, said Chang'e-3 landed on the Sinus Iridum, or the Bay of Rainbows, on the moon's near side, which is as flat as the north China plain, while the landing site of Chang'e-4 is as rugged as the high mountains and lofty hills of southwest China's Sichuan Province.
Chinese space experts chose the Von Karman Crater in the South Pole-Aitken Basin as the landing site of Chang'e-4. The area available for the landing is only one eighth of that for Chang'e-3, and is surrounded by mountains as high as 10 km.
Unlike the parabolic curve of Chang'e-3's descent trajectory, Chang'e-4 made an almost vertical landing, said Wu.
"It was a great challenge with the short time, high difficulty and risks," Wu said.
The whole process was automatic with no intervention from ground control, but the relay satellite transmitted images of the landing process back to Earth, he said.
"We chose a vertical descent strategy to avoid the influence of the mountains on the flight track," said Zhang He, executive director of the Chang'e-4 probe project, from the China Academy of Space Technology.
Li Fei, one of the designers of the lander, said when the process began, an engine was ignited to lower the craft's relative velocity from 1.7 km per second to close to zero, and the probe's attitude was adjusted to face the moon and descend vertically.
When it descended to an altitude of about 2 km, its cameras took pictures of the lunar surface so the probe could identify large obstacles such as rocks or craters, said Wu Xueying, deputy chief designer of the Chang'e-4 probe.
At 100 meters above the surface, it hovered to identify smaller obstacles and measure the slopes on the lunar surface, Wu said.
After calculation, the probe found the safest site, and continued its descent. When it was 2 meters above the surface, the engine stopped, and the spacecraft landed with four legs cushioning against the shock.
The lunar rover for China's Chang'e-4 probe was given the name "Yutu-2" (jade rabbit) after making a soft-landing on the far side of the Moon on Thursday, said China's National Space Administration
Update: 4.01.2019 / 12.30 MEZ
Side of the moon you can't see 'is not dark, it's just far'
This composite image made available by NASA in 2011 shows the far side of Earth's moon. The moon is what scientists call “tidally locked” which means the same side always faces us, while another side always faces away, says Harvard astronomer Avi Loeb. "The other side is not dark, it’s just far.” (NASA
Despite the name of Pink Floyd's best-selling album, the side of the moon you can't see isn't always dark. But it is far.
So scientists call the area where a Chinese spacecraft just landed the far side, not the dark side.
"The other side sees the sun sometimes. The other side is not dark, it's just far," said Harvard astronomer Avi Loeb. "It's a mistake."
The moon is what scientists call " tidally locked " which means the same side always faces us, while another side always faces away, Loeb said. When Earth views a darkened new moon, the far side is lit. When there's a full moon in our sky, the far side is dark.
Every semester, Purdue University lunar and planetary scientist Jay Melosh demonstrates how the far side gets light using a bright light as the sun and students playing the roles of the moon and the Earth. But students still get it wrong on the midterm, calling it the dark side.
Melosh traces the myth back to a Walt Disney television special in 1955 that talked about it always being dark on the other side of the moon and futuristic astronauts dropping flares.
The term dark side really took off in 1973 with the Pink Floyd's mesmerizing album "The Dark Side of the Moon."
While China is the first to land a spacecraft on the far side, there have been plenty of detailed photographs taken by orbiting spacecraft. The first grainy pictures came from a former Soviet Union craft in 1959. NASA's Apollo 8 astronauts saw it first when they orbited the moon 50 years ago.
Chinese media hail Moon probe landing 'for humanity'
Chinese state media and internet users are celebrating the Chang'e-4 probe landing on the far side of the Moon, calling it "a major milestone in space exploration", and comparing it favourably to past American and Russian missions.
State broadcaster China Central Television (CCTV) aired video simulations of the landing a couple of hours after it took place.
Close-up pictures taken by the probe and relayed by the Queqiao (Magpie Bridge) satellite "lifted the ancient mysterious veil" of the far side, the broadcaster said.
'Dream of a shared destiny'
The mission was cast very much as an achievement for the world, not just China.
"The mission achieved humanity's first soft landing of a probe and the first relay communication between the Moon and Earth, opening a new chapter in human lunar exploration," CCTV said.
The nationalist Global Times newspaper contrasted the "open and cooperative" nature of China's space mission with the US' Apollo and Soviet Union's lunar missions, which it described as driven by a "struggle for hegemony".
China's lunar exploration mission "has always harboured the dream of a human community of shared destiny", it said.
"Since the start of our lunar exploration mission, all of our images and data have been presented openly to the international community and used by scientists worldwide," it added.
Questions over deleted tweets
News of the landing also generated some speculation internationally on Twitter, after some journalists and scientists noticed that two state media outlets - the China Daily newspaper and the broadcaster CGTN - deleted tweets confirming that the landing had been a success.
The reason for the deletions is unclear but both outlets later released new tweets on the story, similar to the deleted ones, with only the time of the landing added.
Twitter is largely blocked in China but the topic was also discussed by a few Chinese users on Sina Weibo, China's equivalent of Twitter, which is tightly moderated.
"China Daily and CGTN are both reporting the success of Chang'e-4 on Twitter. But there is no news at all from Xinhua back home," one user noted.
Most users, however - numbering in the millions - expressed congratulations and pride in their country's achievements on Sina Weibo.
On Sina Weibo, the hashtag "Chang'e-4 lands on far side of the moon" was also pinned as an alternating top theme for the day on the platform's "hot search" list, along with news of China's new e-commerce law.
A number of users strongly criticised Sina Weibo for not giving the landing sole top billing.
"Can't this be the top hot search item? Our country is too amazing!" demanded one Weibo user.
"Scum Sina! This should be the first hot search item, OK? Great pride. Childhood dream!" said another, popular Weibo post.
'One giant leap': China's Chang'e 4 rover Jade Rabbit 2 sets off on moon mission
Project leader echoes Neil Armstrong’s quote after rover’s successful separation from lander
China’s space agency has posted the first photo of its Chang’e 4 lunar rover on the far side of the moon after its groundbreaking touchdown on Thursday.
The rover – named Yutu 2, or Jade Rabbit 2 – left the spacecraft, drove off a ramp and began making tracks on the moon’s surface at 10.22pm on Thursday, about 12 hours after Chang’e 4 landed.
Lunar project chief designer Wu Weiren called the separation of the rover “a small step for the rover, but one giant leap for the Chinese nation.”
China’s state news agency, Xinhua, said the probe took a small plant called arabidopsis which is expected to produce the first flower on the moon. Other items included in a mini-biosphere include cotton, rapeseed, potato, fruit fly and yeast.
Thursday’s successful touchdown in the unexplored South Pole-Aitken basin, the biggest known impact structure in the solar system, was hailed a major technical feat and is seen as a important step towards China’s wider ambitions in space. Spacecraft have taken pictures of the moon’s far side before, but no lander has ever landed there.
The moon’s far side is sometimes known as the dark side, although it is not darker than the near side in any literal sense. It undergoes the same phases of illumination by the Sun as the side facing Earth. But because the moon spins on its axis at exactly the same rate as it orbits Earth, one side remains permanently out of view.
It was only in 1959, when the first images of the far side were beamed back by the Soviet Union’s Luna 3, that intriguing differences were revealed. The far side is pockmarked by more craters and appears almost devoid of the seas of solidified lava, known as maria, that form the shadowy shape of a face that we see from Earth.
The mission will also conduct the first astronomy observations from the moon’s far side, which is seen as a uniquely attractive site for monitoring radio waves coming from deep space. Astronomers operating Earth-bound radio telescopes have to constantly grapple with electromagnetic interference from human activity: shortwave broadcasting, maritime communication, telephone and television signals. The far side of the moon is shielded from such signals, making it far easier to pick up faint fingerprints left by the Big Bang.
The craft is also carrying a mini-greenhouse, which will test how well plants, specifically potatoes and small flowering Arabidopsis plants, related to cabbage, grow on the moon.
China's Yutu 2 Rover Is Driving on the Far Side of the Moon
The lunar far side now has its first set of rover tracks.
Last night (Jan. 2), China's robotic Chang'e 4 lander-rover duo pulled off the first-ever soft touchdown on the moon's largely unexplored far side. And today (Jan. 3), the rover rolled onto the gray dirt floor of the 115-mile-wide (186 kilometers) Von Kármán Crater, creeping down twin ramps from a previous position atop the stationary lander.
Also today, China revealed the name of the rover: "Yutu 2." This moniker may not be terribly creative, but it makes a lot of sense. The original Yutu rover touched down, along with a lander, on the moon's near side in December of 2013 on the Chang'e 3 mission. And Chang'e 4 was originally designed as a backup for Chang'e 3, so the two missions share a lot of hardware.
China's Yutu 2 rover makes the first wheel tracks on the far side of the moon on Jan. 3, 2019, after rolling down from the Chang'e 4 lander.
Yutu 2 and its lander companion will conduct the first in-depth science investigations on the far side. The two craft tote four science instruments each, and these will enable the pair to characterize the surface and near subsurface of Von Kármán in great detail. This crater lies within an even larger impact feature, the 1,550-mile-wide (2,500 km) South Pole-Aitken Basin.
The lander also carries a biological experiment: a small tin containing silkworm eggs and the seeds of several plant species, including potatoes. Mission team members aim to study how these organisms grow and develop in the low-gravity lunar environment.
A close-up of one of Yutu 2's wheels.
The lander and Yutu 2 cannot beam their data home to Earth directly, because the moon's far side always faces away from our planet. Indeed, this communication complication is a big reason why the far-side surface had not previously welcomed any functioning spacecraft (though a few probes have crashed there over the years).
So, the Chang'e 4 duo will rely on a relay satellite called Queqiao, which China launched to a gravitationally stable point beyond the moon in May 2018. From its vantage point, Queqiao can keep Yutu 2, the lander and Earth all in sight at the same time.
Chang'e 4 is the latest step in China's ambitious program of robotic lunar exploration, with the satellite taking its name from a moon goddess in Chinese mythology. (In this mythology, by the way, Yutu is the pet rabbit of Chang'e.) The Chang'e 1 and Chang'e 2 missions sent orbiters to the moon in 2007 and 2010, respectively, and Chang'e 3 aced its near-side touchdown in late 2013.
Then, in October 2014, the Chang'e 5T1 mission launched a prototype capsule on an eight-day trip around the moon. The main goal was to help prove out technology required for the Chang'e 5 sample-return mission, which could launch as early as this year.
China Focus: China's upgraded lunar rover drives on moon's far side
BEIJING, Jan. 4 (Xinhua) -- China's second lunar rover has driven on the far side of the moon, which is expected to bring more scientific discoveries from the alien world.
The new rover, named Yutu-2, or literally Jade Rabbit-2, separated from the lander and descended on the lunar surface Thursday night, leaving the first "footprints" on the loose lunar soil, which will be seen for thousands of years as the moon has no wind or rain.
Although the rover of the Chang'e-4 probe looks similar to its predecessor Yutu of the Chang'e-3 probe, Chinese space engineers have made it lighter, smarter, stronger and more reliable.
In Chinese folklore, Yutu is the white pet rabbit of Chang'e, the moon goddess who lent her name to the Chinese lunar mission.
Scientists hope Yutu-2 will travel farther to send more images of the unknown terrain, "listen" to the stories recorded in the ancient lunar rocks, and find more traces of the early history of the moon and the solar system.
The 135-kg new rover is 2 kg lighter than its predecessor and is the lightest rover ever sent to the moon, said Jia Yang, deputy chief designer of the Chang'e-4 probe, from the China Academy of Space Technology (CAST).
The main reason for the weight reduction is the removal of a robotic arm and its replacement with an instrument developed by Swedish scientists to analyze the radiation environment on the lunar surface, said Jia.
Like Yutu, which landed on the moon at the end of 2013, the new rover carries subsurface penetrating radar to detect the near-surface structure of the moon and an infrared spectrometer to analyze the chemical composition of lunar substances.
Two panoramic cameras, like two eyes, can take high-resolution, color images.
The rover, with a design life of three months, can cross rocks as high as 20 cm, at a maximum speed of 200 meters per hour.
At nighttime on the moon, temperatures can drop to about negative 180 degrees Celsius. During the Chang'e-3 mission, the ground control center instructed that the rover would remain dormant each night, said Zhang He, executive director of the Chang'e-4 probe project, from CAST.
Once the sun would rise, Yutu would wake automatically, but it needed ground control to instruct it to start the work mode, Zhang said.
However, Yutu-2 will automatically enter the dormant state according to the level of sunlight, and it can also enter the work state on its own.
"We made this adjustment because communication between ground control and the Chang'e-4 probe on the far side of the moon is not as convenient as communication with Chang'e-3 on the near side," said Zhang.
China's first lunar rover Yutu suffered a mechanical fault after driving about 114 meters five years ago.
"How to solve that problem so that it won't happen again was the main challenge in developing the new rover," said Zhang Yuhua, another deputy chief designer of the probe.
"We have improved the layout of the wires on the new rover and taken measures to prevent short circuits. We also made a fault isolation design so that if a problem occurs, it will not affect the whole system," said Sun Zezhou, chief designer of the Chang'e-4 probe.
"Compared with Yutu, our second rover is stronger," said Shen Zhenrong, a designer of the rover, from CAST.
"We are confident our new rover can run farther on the moon and obtain more scientific results," Sun said.
China Focus: Scientists expect breakthrough findings on moon's far side
BEIJING, Jan. 4 (Xinhua) -- China's Chang'e-4 probe has landed on the South Pole-Aitken (SPA) Basin on the far side of the moon, regarded as a virgin territory by scientists expecting important discoveries.
"The far side of the moon has very unique features, and has never been explored in situ, so Chang'e-4 might bring us breakthrough findings," said Zou Yongliao, director of the lunar and deep space exploration division of the Chinese Academy of Sciences (CAS).
As a result of the tidal locking effect, the moon's revolution cycle is the same as its rotation cycle. It always faces the earth with the same side, and the far side was a mystery before the age of spacecraft.
About 60 years ago, the Luna 3 probe of the Soviet Union sent back the first image of the moon's far side. And about 50 years ago, three astronauts of the United States Apollo 8 mission became the first people to see the moon's far side with their own eyes.
More lunar missions showed the moon's two sides were very different: the near side has more and relatively flat lunar mares, while the far side is thickly dotted with impact craters at different sizes.
"There are great differences in terms of substance composition, terrain and landforms, structure and the age of rocks. For instance, about 60 percent of the near side is covered by mare basalt, but most part of the far side is covered by lunar highland anorthosite. Of the 22 lunar mares, 19 are located on the near side," said Zou.
Scientists infer that the lunar crust on the far side is much thicker than the near side. But why is still a mystery. Only in-situ exploration might reveal the secrets.
Exploration of the far side might help shed light on the early history of the moon, the earth and the solar system.
The moon and the earth shared a similar "childhood." But the traces of the remote past on earth have been erased by geological activity. "The moon might provide us with some insights to the early history of earth," said Lin Yangting, a researcher from the Institute of Geology and Geophysics of CAS.
The SPA Basin, where the Chang'e-4 probe landed, is the largest and deepest basin in the solar system, with a diameter of 2,500 km and a depth of more than 10 km.
"With the Chang'e-4 probe, we can detect information hidden deeply inside the moon. I believe there will be surprising scientific findings," Zou said.
"The rocks on the far side are more ancient. The analysis of their substance composition might help us better understand the evolution of the moon," said Zou.
Scientists have found evidence indicating a heavy asteroid bombardment event in the solar system around 3.9 billion years ago. And the SPA Basin might be an impact from that period. The exploration might offer clues as to why the bombardment occurred, said Zou.
The Chang'e-4 probe is equipped with instruments developed by scientists from Sweden, Germany and China to study the lunar environment, cosmic radiation and the interaction between solar wind and the moon surface.
Cosmic radiation and solar wind might harm people and equipment on the moon. If humans want to return there, it is essential to investigate the lunar environment and radiation in preparation for the mission.
Astronomers are also seeking a completely quiet electromagnetic environment to detect weak signals emitted from remote celestial bodies in deep space.
The far side is such a place, as the body of the moon shields against radio interference from the earth. From there, astronomers can study the origins and evolution of stars and galaxies, peering into the dawn of the universe.
"Conducting low-frequency radio astronomical observation on the far side is a long cherished goal of astronomers, and could fill gaps in astronomical observation,"said Zou.
Low-frequency radio detectors, developed by Chinese and Dutch scientists, are installed on the Chang'e-4 lander, a micro satellite orbiting the moon, and the relay satellite running around the second Lagrangian (L2) point of the earth-moon system, respectively.
China's 'Yutu 2' Chang'e-4 rover is now rolling on the far side of the Moon
The Chang'e-4 'Yutu 2' rover was deployed on the lunar surface at 14:22 UTC, December 3, 2018.CLEP/CNSA
China's Chang'e-4 mission rover mission rover has rolled down from the lander onto the lunar surface following Thursday's historic landing on the far side of the Moon.
The Chang'e-4 spacecraft had made its descent from lunar orbit and into the pre-selected landing area with the Von Kármán crater at 02:26 universal time Thursday (10:26 Beijing time).
The lander returned the first ever images from the surface of the far side of the morning shortly after, with images from its descent and others cameras sent to Earth via the Queqiao relay satellite.
Almost twelve hours later the China Lunar Exploration Project (CLEP) announced that the rover had descended from atop the lander at 14:22 UTC.
Close-up view of the wheel of the Chang'e-4 rover 'Yutu 2 (Jade Rabbit 2). CLEP/CNSA
CLEP also revealed that the rover would be named Yutu 2 (Jade Rabbit 2), following on from the rover for the Chang'e-3 mission which landed on Mare Imbrium on the near side of the Moon in December 2013.
The name came from a public contest to elicit names, a vote from a shortlist and final decision by committee. 'Brightness' (光明, guangming), 'Wang Shu' (望舒) and 'Stroller' or 'Hiker' (行者, xingzhe) had appeared more popular.
China's Chang'e-3 lander and Yutu (Jade Rabbit) rover operating on the Moon after landing in late 2013.
Chang'e-4 landed at 177.6 degrees east longitude and 45.5 degrees south following a 12-minute powered descent.
Yutu will rove within Von Kármán craterand analyse the variations of composition of the lunar surface the Visible and Near-Infrared Imaging Spectrometer (VNIS), while also returning unprecedented images with a panchromatic camera.
The rover's two offer science payloads, the Lunar Penetrating Radar (LPR) and Advanced Small Analyser for Neutrals (ASAN), the latter developed by the Swedish Institute of Space Physics in Kiruna, will provide insight into the lunar subsurface to a potential depths of hundreds of metres and the space environment and interactions with the surface respectively.
Chang’e-4 lands on the Moon and sends back first images
Update: 20.00 MEZ
Und Yutu (Jade Rabbit) Rover rollt, und rollt:
Astronomers worldwide hail China's successful landing of Chang'e-4 lunar probe
BEIJING, China's successful landing of Chang'e-4 spacecraft on the dark side of the moon is hailed by astronomers worldwide as a great achievement, and many expect breakthrough findings from the probe.
NASA Administrator Jim Bridenstine said on his twitter account Thursday that the landing is "a first for humanity and an impressive accomplishment!"
Johan Koehler, head of Solar System Science and Space Situational Awareness, Swedish National Space Agency, said exploration of the far side of the moon was a great achievement by China. "We are very happy to be a part of it."
The Chang'e-4 probe is equipped with instruments developed by scientists from Sweden, Germany and China to study the lunar environment, cosmic radiation and the interaction between solar wind and the moon surface.
"There is a theory that water on the surface of the moon is formed by the interaction of solar wind with the surface regolith. So this is something that Swedish scientists together with Chinese scientists want to answer," said Koehler.
Ian Crawford, professor of planetary science and astrobiology at Birkbeck, University of London, told SpaceNews Magazine based in the United States ahead of the event that a safe landing would be a "fantastic achievement."
"This will give valuable information on the composition of the far side crust and, conceivably, the upper mantle ... The radio astronomy experiments are also of great interest, which may lay a foundation for the development of lunar far side radio astronomy," Crawford said.
Fred Watson, who promotes Australia's astronomy endeavours as its astronomer-at-large, told BBC that "the Chinese space agency is a young organisation, but perhaps in years to come, it will catch up."
Landing on the unexplored and rugged far side of the moon is not easy, and Chang'e-4 is the first craft that has ever made it.
"Landing on the far side of the moon is an amazing technical achievement because there is a significant amount of time when the vehicle is out of contact with earth," said Eugenio Fontan, the Managing Director of the Madrid Aerospace Cluster.
"The Chinese probe has had to land on its own. That is something very few space agencies have the capacity to do," he highlighted.
The moon is tidally locked to earth, rotating at the same rate that it orbits Earth, so only one side of the moon is seen from Earth, leaving the far side a complete mystery, until now.
"The far side of the moon has unique features never before explored on site," said Zou Yongliao, director of the lunar and deep space exploration division of the Chinese Academy of Sciences (CAS). "The exploration of this virgin land by Chang'e-4 might bring breakthroughs."