Humanity first visited the moon decades ago, but today is the first time a mission has made a soft landing on the moon's far side.
A Chinese space probe successfully touched down on the far side of the moon on Thursday, China's space agency said, hailing the event as a historic first and a major achievement for the country's space program.
As China's space agency CNSA explains in a new post on its website, the Chang'e 4 lander arrived on schedule on the Moon's surface and quickly deployed the Yutu rover.
In 2013, the predecessor spacecraft Chang'e 3 made the first moon landing since the former Soviet Union's Luna 24 in 1976.
The far-side landing is China's first attempt at "something that other space powers have not attempted before", Ye Quanzhi, an astronomer at Caltech, told the BBC.
"This time the Chang'e-4 mission have a very good start. The back of the moon is also a rare quiet place that shields the radio signal interference from the Earth".
The far side of the moon faces away from Earth and is relatively unexplored. So in the future I believe that China's lunar exploration project has three steps - orbiting, landing, and also sample return. 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.
The Queqiao satellite is deployed about 455,000 kilometers from Earth, where it will relay communications between ground controllers and the Chang'e-4.
This may reinforce the concern of some lunar scientists and spaceflight experts, who warn that if we want to see the Moon developed under Western norms of freedom and openness, then NASA and United States businesses had better lead the return and development of the Moon during the coming decade. That was China's first moon landing and the beginning of its second mission phase. Radio waves can't reach around the moon from the far side without some kind of relay system, and Queqiao provides the missing link. Its plans include establishing a permanent manned space station, a manned lunar landing, and eventually probes to Mars.