A Chinese lunar probe's successful landing on the far side of the Moon has been hailed as a milestone in the history of space exploration and the country's quest to reach the top of this field.
The Chang'e-4 made a soft landing on the unexplored outer-reaches of the Moon at 10.26am yesterday, sending back the first close-range pictures via the Chinese-built relay satellite Queqiao (Magpie Bridge) of that astronomical neighbourhood.
Launched from Xichang in southwest China's Sichuan province on Dec 8, the spacecraft is on a mission to seek out what lies on this mysterious "dark side" of the Moon, which cannot be seen from the Earth as the Moon is tidally locked to the Earth and rotates at the same rate that it orbits the Earth.
In a statement yesterday, the China National Space Administration said its triumphant touchdown has "opened a new chapter in human lunar exploration", and it is "willing to cooperate with space agencies, space and science research institutions and foreign space and science enthusiasts from all over the world to explore the mysteries of the universe".
More than a hundred agency personnel watched nervously from the Beijing Aerospace Flight Control Centre as the probe began to reduce power 15km from the Moon. As it hovered about 100m above the lunar surface, detectors looked for obstacles before settling on a flat area - the Von Karman crater in the South Pole-Aitken Basin on the back of the Moon.
This southern hemisphere of the Moon features a more rugged terrain which makes landing harder. The South Pole-Aitken Basin, which measures 2,500km in diameter and is 13km deep, is also the largest, deepest and oldest impact crater on the Moon, and may yield secrets of its evolution to the Chang'e-4.
The probe, which has a lander and a rover, will conduct surveys on terrain, mineral composition and other environmental qualities in collaboration with countries including the Netherlands, Germany, Sweden and Saudi Arabia.
It also carried cotton, rapeseed, potato, Arabidopsis, fruit fly and yeast samples to form a mini biosphere in the lifeless environment, said state news agency Xinhua.
Macau University of Science and Technology professor Zhu Menghua called the landing "absolutely perfect" and a "big milestone" for China's space exploration because of the technical difficulties of landing in an uncharted territory.
"The exploration will give us more information about the Moon than we have ever known, and that is critical," said Prof Zhu.
Since launching its first astronaut into space in 2003, China has been on an ambitious drive to catch up with the pack led by the United States. Previously, the US and the former Soviet Union were the only countries that had managed Moon landings.
China's first lunar lander, the Chang'e-3, soft-landed on the near-side of the Moon in 2013, becoming the first spacecraft to do so since the Soviet Union's Luna 24 in 1976.
The latest lunar landing is but one box that the Chinese space agency has ticked off. It plans to start operating its first space station by 2022, launch probes to Mars and send astronauts out again.
While the US and Russia have the capacity to launch a similar landing on the far side, China has beaten them to it this time, though its academics put that in perspective.
"China has never said it is in a space race with the US, and has no such intention," said Professor Wang Xiangsui, director of the Research Centre of Strategic Issues at Beihang University. "The US is definitely still the leader in space technology, but China is catching up."