Chang'e 5's probe gathers samples on the moon on Dec 2, 2020. (PHOTO / XINHUA)

About 1,731 grams of lunar rocks and soil brought back by China's Chang'e 5 robotic probe were transferred to Chinese scientists for research on Saturday morning, according to the China National Space Administration.

The samples were handed over by Zhang Kejian, head of the space administration, to Hou Jianguo, president of the Chinese Academy of Sciences, at a delivery ceremony in Beijing held by the space administration.

The delivery marked the start of research into the samples, the administration said in a statement, adding that it will publish guidelines on the samples' distribution and use and will also encourage scientists from around the world to participate.

Chang'e 5, China's largest and most advanced lunar probe, was launched by a Long March 5 heavy-lift carrier rocket early on Nov 24 at the Wenchang Space Launch Center in southern China's Hainan province, setting out on China's most difficult space mission and the world's first to retrieve lunar samples since 1976.

The 8.2 metric ton spacecraft consisted of four main components-an orbiter, lander, ascender and reentry capsule.

The probe separated into two parts - the orbiter-reentry capsule combination and the lander-ascender combination - while in lunar orbit on Nov 30.

On Dec 1, the lander-ascender combination landed on the moon, becoming the world's third spacecraft to touch down on the lunar surface this century, after its predecessors - Chang'e 3 and 4.

The delivery marked the start of research into the samples, China National Space Administration said in a statement, adding that it will publish guidelines on the samples' distribution and use and will also encourage scientists from around the world to participate

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The landing site was near Mons Ruemker, an isolated volcanic formation located in the Oceanus Procellarum, or the Ocean of Storms, on the western edge of the moon's near side. The area had never been visited before Chang'e 5.

Shortly after landing, the combination began to fulfill its major tasks of using a drill to obtain underground samples and then using a mechanical arm to scoop surface soil.

The collection operations finished on Dec 2, taking about 19 hours, which was much quicker than expected. Samples were packed into a vacuum container inside the ascender.

During the process, the lander also unfurled the first free-standing Chinese national flag on the lunar surface.

The ascender activated an engine on Dec 3 to lift itself into an elliptical lunar orbit to prepare for docking with the reentry capsule, marking the first time a Chinese spacecraft has blasted off from an extraterrestrial body.

It linked up with the orbiting combination on Dec 6 and transferred the lunar samples into the reentry capsule. The ascender separated from the combination later that day and was commanded to impact on the moon on Dec 8.

The combination made two orbital maneuvers over the weekend after traveling in a near-circular lunar orbit for nearly six days. After the maneuvers, the pair entered a moon-Earth transfer trajectory on Sunday and began to fly back toward Earth.

The pair separated from each other early on Thursday morning, and the reentry capsule, laden with lunar samples, soon touched down on grassland on its preset landing site in Siziwang Banner of the Inner Mongolia autonomous region.

READ MORE: Chang'e-5 completes first orbital correction en route to Earth

The capsule was transported by plane to Beijing on Thursday afternoon, and was initially handled by experts at the China Academy of Space Technology.

The mission was the first in the world in more than 40 years to bring lunar samples back to Earth, also making China the third country to achieve this feat after the United States and the former Soviet Union.

With Xinhua inputs