BANGKOK — China's Chang'e 6 probe returned on Earth with rock and soil samples from the little-explored far side of the moon in a global first.
The probe landed in the Inner Mongolian region in northern China on Tuesday afternoon.
''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 anticipate the returned samples will include 2.5 million-year-old volcanic rock and other material that scientists hope will answer questions about geographic differences on the moon's two sides.
The near side is what is seen from Earth, and the far side faces outer space. The far side is also known to have mountains and impact craters, contrasting with the relatively flat expanses visible on the near side.
The probe had landed in the moon's South Pole-Aitken Basin, an impact crater created more than 4 billion years ago. 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 chronology, such as when the moon was younger and had an active inside that could produce volcanic rock.
While past U.S. and Soviet missions have collected samples from the moon's near side, the Chinese mission was the first that has collected samples from the far side.
"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.