Many lunar probes have taken samples from the Moon. But until now, none took samples from the far side of the Moon, even though the far side of the Moon is very different from the side that faces the Earth, with a more rugged surface pockmarked by craters. So we don’t have a full picture of what the far side of the Moon is like.
This month, a Chinese probe began collecting soil samples from the Moon’s far side, the first lunar probe to ever do so.
As Wikipedia notes,
The far side of the Moon is the lunar hemisphere that always faces away from Earth,…Compared to the near side, the far side’s terrain is rugged, with a multitude of impact craters and relatively few flat and dark lunar maria (“seas”), giving it an appearance closer to other barren places in the Solar System such as Mercury and Callisto. It has one of the largest craters in the Solar System, the South Pole–Aitken basin….About 18 percent of the far side is occasionally visible from Earth due to oscillation and to libration. The remaining 82 percent remained unobserved until 1959, when it was photographed by the Soviet Luna 3 space probe…. All crewed and uncrewed soft landings had taken place on the near side of the Moon, until January 3, 2019, when the Chang’e 4 spacecraft made the first landing on the far side. The Chang’e 6 sample return mission was launched on May 3, 2024, and landed in the Apollo basin to collect the first samples from the far side.
A news report explains:
The Chang’e-6 probe touched down on the Moon’s South Pole-Aitken Basin where it will soon begin to drill into the Lunar soil—known officially as ‘regolith.’
It follows five successful lunar missions (Chang’e 1 through 5) that included establishing a weather station on the Moon’s far side in Chang’e-4—the first time any craft had made it there, and a sample return mission from the polar region with Chang’e-5, which brought back the first Lunar samples since the Apollo missions.
It’s believed that the Apollo Crater in which Chang’e-6 landed contains some of the oldest regolith on the Moon, dating back 4 billion years to the earliest formations of the Earth.
Chang’e-6 contains an orbiter, lander, ascent vehicle, and re-entry module. The land’s mechanical drill arm will gather and stow the samples before blasting them up into space in the ascent vehicle which will be picked up by the orbiter, and sent back to Earth in the re-entry.
All this will be commanded and controlled through the Queqiao-2 satellite because normal communications are blocked on the Moon’s far side. If successful, China will become the first nation to land and sample on the far side.This is the last sample-return mission in the Chang’e mission series, with missions 7 and 8 slated for in-situ experiments destined to inform and assist a permanent Chinese robotic base on the Moon.
