China has become the first country to ever land on the dark side of the Moon, touching down late in a historic landing that shows its fast-growing spaceflight capabilities.
Their Chang’e 4 lander, named Yutu 2 after a public naming contest, touched down near a region called the South Pole-Aitken Basin at about 2.26am UTC today, January 3. China’s state-run news networks, including China Global Television Network (CGTN), posted the news on Twitter after a lack of information in the run-up to the landing.
“China’s Chang’e-4 probe lands successfully on far side of the moon,” the CGTN wrote on Twitter, “marking the first ever soft-landing in this uncharted area.”
Chang’e 4, which launched from the Xichang Satellite Launch Center on December 7, 2018, is the second lander and rover China has sent to the Moon, after the twin Chang’e 3 mission in 2013. That mission landed on the Moon’s near-side, however, which has been explored before by the US and the Soviet Union. Chang’e 4 instead attempted something never done before.
The mission consists of a stationary lander weighing about 1,200 kilograms (2,600 pounds), and a rover weighing about 140 kilograms (310 pounds). At 2.22pm UTC, the rover rolled down from the lander onto the surface of the Moon.
As the Moon is tidally locked to Earth, one side of it always points towards our planet, and the other – the far side – always points away. Although spacecraft have orbited the Moon and imaged the far side, no one has landed there due in part to the technological challenges.
In order to communicate with its lander on the far side, China launched a relay satellite called Queqiao in May 2018 into a gravitationally stable location 65,000 kilometers (40,000 miles) beyond the Moon. Here, this satellite is both in sight of the lander and Earth, so all communications can be passed through it.
The landing itself was largely autonomous, however, with the lander touching down in a region known as the Von Kármán Crater. This is located within the South Pole-Aitken Basin, which at 2,500 kilometers (1,600 miles) across is the largest impact crater on the Moon.
It’s hoped that this region could contain some fascinating details about the Moon’s history. Some of the Moon’s mantle is believed to have been pulled up to the surface in this location, which Chang’e 4 will be able to study.
The mission also has three cameras, which will be used to return stunning images to Earth, and a ground-penetrating radar, which will be able to peer 100 meters (330 feet) below the surface. There are also two European experiments on board to study incoming particles on the Moon.
The Moon takes 28 days to rotate, giving most regions 14 days of sunlight and 14 days of night. Chang’e 4 has landed as close to the start of day at its location as possible, which began on December 30. This will give its solar panels ample sunlight, before freezing temperatures accompany lunar night in mid-January.
All eyes will now be on how much this mission can achieve. The rover on the Chang’e 3 mission failed to last the lunar night, but its lander – called Yutu – is still operational today. Whatever Chang’e 4 achieves from now on will be a bonus, on top of what has already been a historic landing in the history of spaceflight.