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 — believed to be up to 2.5 million years old — landed in the country’s Inner Mongolia region on Tuesday in a major victory for the China National Space Administration (CNSA).

“I now declare that the Chang’e 6 Lunar Exploration Mission achieved complete success,” Zhang Kejian, Director of the China National Space Administration, said in a televised news conference after the landing.

Chinese scientists hope they will be able to learn about the geographic differences between the two sides of the moon and offer some insight into its ancient history.

The near-side faces Earth and the far-side faces outer space. While the moon does spin on its own axis, the moon rotates at the same rate as its orbital motion, meaning the same side always faces the Earth.

The far side of the moon, whose surface has never been explored, is known to have large mountains and deep craters compared to the relative flatness of the near-side.

The unmanned probe, launched on May 3, landed on the moon’s South Pole-Aitken Basin — an impact crater formed more than 4 billion years ago when Earth was still in its infancy. It remained in space for 53 days.

The samples scientists are expecting will likely come from different layers of the basin, which will bear traces of the different geological events across its long cosmic history, such as when the moon was younger and had an active core that produced volcanic rock.

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 issued in the Innovation Monday, a journal published in partnership with the Chinese Academy of Sciences.

China is the first country to land on the moon’s far side, with previous US and Soviet missions all landing on the near-side.

The moon program is part of a growing rivalry with the US — still the leader in space exploration — and other nations, including Japan and India. 

China’s leader Xi Jinping congratulated the Chang’e team, saying the mission was a “landmark achievement in our country’s efforts at becoming a space and technological power.”

China has put its own space station in orbit and regularly sends crews there.In recent years, China has sent multiple successful missions to the moon, collecting samples from the moon’s 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,” Richard de Grijs, a professor of astrophysics at Macquarie University in Australia, told the Associated Press.

With Post wires