China says its uncrewed craft has successfully landed on the far side of the Moon - an unexplored place almost no-one tries to go.
The Chang'e 6 touched down in the South Pole-Aitken Basin at 06:23 Beijing time on Sunday morning (22:23 GMT Saturday), the China National Space Administration (CNSA) said.
Launched on 3 May, the mission aims to collect precious rock and soil from this region for the first time in history.
The probe could extract some of the Moon's oldest rocks from a huge crater on its South Pole.
The landing was fraught with risks, because it is very difficult to communicate with spacecraft once they reach the far side of the Moon. China is the only country to have achieved the feat before, landing its Chang'e-4 in 2019.
After launching from Wenchang Space Launch Center, the Chang'e 6 spacecraft had been orbiting the Moon waiting to land.
The lander component of the mission then separated from the orbiter to touch down on the side of the Moon that faces permanently away from Earth.
During the descent, an autonomous visual obstacle avoidance system was used to automatically detect obstacles, with a visible light camera selecting a comparatively safe landing area based on the brightness and darkness of the lunar surface, the CNSA was quoted as saying by state-run Xinhua news agency.
The lander hovered about 100m (328ft) above the safe landing area, and used a laser 3D scanner before a slow vertical descent.
The operation was supported by the Queqiao-2 relay satellite, the CNSA said.
Chinese state media described the successful landing as an “historic moment”.
The state broadcaster said “applause erupted at the Beijing Aerospace Flight Control Center” when the Chang’e landing craft touched down on the Moon early on Sunday morning.
The lander should spend up to three days gathering materials from the surface in an operation the CNSA said would involve "many engineering innovations, high risks and great difficulty".
"Everyone is very excited that we might get a look at these rocks no-one has ever seen before," explains Professor John Pernet-Fisher, who specialises in lunar geology at the University of Manchester.
He has analysed other lunar rock brought back on the American Apollo mission and previous Chinese missions.
But he says the chance to analyse rock from a completely different area of the Moon could answer fundamental questions about how planets form.
Most of the rocks collected so far are volcanic, similar to what we might find in Iceland or Hawaii.
But the material on the far side would have a different chemistry .
"It would help us answer those really big questions, like how are planets formed, why do crusts form, what is the origin of water in the solar system?" the professor says.
The mission aims to collect about 2kg (4.4lb) of material using a drill and mechanical arm, according to the CNSA.
The South Pole–Aitken basin, an impact crater, is one of the largest known in the solar system.
From there, the probe could gather material that came from deep inside the lunar mantle - the inner core of the Moon - Prof Pernet-Fisher says.
The Moon's South Pole is the next frontier in lunar missions - countries are keen to understand the region because there is a good chance it has ice.
The capsule in the last Chinese moon mission, Chang'e 5, brought back soil and rocks in 2020
Access to water would significantly boost the chances of successfully establishing a human base on the Moon for scientific research.
If the mission succeeds, the craft will return to Earth with the precious samples on board a special return capsule.
The material will be kept in special conditions to try to keep it as pristine as possible.
Scientists in China will be given the first chance to analyse the rocks, and later researchers around the world will be able to apply for the opportunity too.
This is the second time China has launched a mission to collect samples from the Moon.
In 2020 Chang'e 5 brought back 1.7kg of material from an area called Oceanus Procellarum on the Moon's near side.
China is planning three more uncrewed missions this decade as it looks for water on the Moon and investigates setting up a permanent base there.
Beijing's broader strategy aims to see a Chinese astronaut walk on the moon by around 2030.
The US also aims to put astronauts back on the moon, with Nasa aiming to launch its Artemis 3 mission in 2026.