A press conference on Chang'e-6 mission is held by China's State Council Information Office in Beijing, capital of China, June 27, 2024. (Xinhua/Jin Liwang)

The weight of the samples collected from the far side of the moon by the Chang'e-6 mission will be made public on Friday, the China National Space Administration (CNSA) said on Thursday.

Hu Hao, chief designer of the Chang'e-6 mission, revealed his initial impressions of the lunar soil samples at a press conference held by the CNSA.

"The lunar soil samples from the moon's near side are fine and loose, while the samples from the far side appear to be different. So, we have higher expectations for the new lunar samples and hope that scientists will make new discoveries," Hu said.

According to Hu, the Chang'e-6 mission encountered many challenges, one of which was communicating with Earth from the far side of the moon. To solve this problem, China launched the Queqiao-2 relay satellite in March to provide relay communication support for the mission.

Additionally, the terrain and landforms on the far side of the moon are much more complex than on the near side, said Li Chunlai, deputy chief designer of the Chang'e-6 mission. "We have overcome many difficulties in landing and collecting samples."

Hu also highlighted that the sampling device developed by a research team at the Hong Kong Polytechnic University enabled the mission to be completed smoothly.

"I believe that Chang'e-6 carried out its sampling work more smoothly than Chang'e-5, with each sampling operation obtaining more samples than expected," he said.

"During previous lunar sample research, we received applications from several universities and research institutions in Hong Kong, which also obtained samples. The results of research on the Chang'e-6 samples are even more promising, and we hope they will actively participate in that too," he added.

Previous lunar sampling missions all collected samples from the moon's near side. The Chang'e-6 probe has successfully collected samples from the far side of the moon for the first time, which is expected to provide an opportunity for a more comprehensive understanding of the moon, said Li Chunlai, deputy chief designer of the Chang'e-6 mission.

The Chang'e-6 probe landed and collected samples in the South Pole-Aitken (SPA) Basin. The colossal SPA Basin was formed by a celestial impact over 4.3 billion years ago and has a diameter of 2,500 km and a depth of about 13 km. It is believed to be the largest impact crater found in the inner solar system so far.

"As the sampling site was in a huge impact basin, it was possible to collect samples from the deep part of the moon and even from the lunar mantle," Li said. "The deep materials are very precious and difficult to obtain, and they will provide valuable data for us to understand the internal structure of the moon and its material composition."

They will also help in the study of the solar system's early evolutionary history, and promote research on comparative planetology, Li added.

The Chang'e-6 probe, comprising an orbiter, a lander, an ascender and a returner, was launched on May 3. Its returner carrying the samples touched down on Earth on Tuesday.

In December 2020, China's Chang'e-5 probe retrieved approximately 1,731 grams of samples from the moon.

According to Bian Zhigang, deputy head of the CNSA, Chinese and foreign scientists have published more than 1,900 papers using data from China's lunar exploration.

From the lunar samples collected by the Chang'e-5 probe, Chinese scientists discovered a sixth new mineral on the moon, naming it Changesite-(Y). Research has proved that magma activity existed on the moon 1.96 billion years ago, extending the known geological life of the moon by 1 billion years, Bian added.