China's lunar probe returns to Earth with first-ever rock samples from 'dark side' of moon

China's Chang'e-6 lunar probe has successfully returned to Earth with the first rock and soil samples ever collected from the far side of the moon.

The re-entry capsule containing the samples, which are believed to be up to 2.5 million years old, landed in Inner Mongolia on Tuesday, marking a significant achievement for the China National Space Administration (CNSA), reports The New York Post.

"I now declare that the Chang'e-6 Lunar Exploration Mission achieved complete success," announced Zhang Kejian, Director of the CNSA, during a televised news conference following the landing.

Chinese scientists aim to analyze these samples to understand the geographic differences between the moon's near side and far side, providing insights into its ancient history. The near side always faces Earth, while the far side faces outer space. Although the moon rotates on its axis, it does so at the same rate as its orbit, causing the same side to perpetually face Earth.

The far side, which has not been explored before, is characterized by large mountains and deep craters, in contrast to the near side's relative flatness.

The unmanned Chang'e-6 probe, launched on May 3, landed in the moon's South Pole-Aitken Basin, an impact crater formed over 4 billion years ago. It remained in space for 53 days.

The samples, likely from different layers of the basin, will contain traces of various geological events throughout its history, including volcanic activity from the moon's younger, active core.

The samples "are expected to answer one of the most fundamental scientific questions in lunar science research: what geologic activity is responsible for the differences between the two sides?" said Zongyu Yue, a geologist at the Chinese Academy of Sciences, in a statement in the journal Innovation Monday, published in partnership with the Chinese Academy of Sciences.

China is the first nation to land on the moon's far side, with prior US and Soviet missions all targeting the near side.

This moon program is part of China's growing competition with the US and other countries, including Japan and India, in space exploration.

China's leader Xi Jinping praised the Chang'e team, calling the mission a "landmark achievement in our country's efforts at becoming a space and technological power."

China has launched its own space station and regularly sends crews there. In recent years, China has also completed multiple successful lunar missions, including collecting samples from the near side with the Chang'e-5 probe.

"This is a global first in the sense that it's the first time anyone has been able to take off from the far side of the moon and bring back samples," said Richard de Grijs, a professor of astrophysics at Macquarie University in Australia, to the Associated Press.