China is about to launch the first mission to land robotic craft on the far side of the Moon.
The Chang’e-4 mission will see a static lander and rover touch down in Von Kármán crater, located on the side of the Moon which never faces Earth.
The payload is set to launch on a Long March 3B rocket from Xichang Satellite Launch Center at about 18:30 GMT.
The mission will pave the way for the country to deliver samples of Moon rock and soil to Earth.
The landing will not occur until early January, when the probe will descend on thrusters and touch down on the rugged terrain of the lunar far side.
Von Kármán crater is of interest to scientists because it is located within the oldest and largest impact feature on the Moon – the South Pole-Aitken Basin. This was probably formed by a giant asteroid impact billions of years ago.
The landers will characterise the region’s geology and the composition of rock and soil.
Because of a phenomenon called “tidal locking”, we see only one “face” of the Moon from Earth. This is because the Moon takes just as long to rotate on its own axis as it takes to complete one orbit of Earth.
The far side looks rather different to the more familiar near side. It has a thicker, older crust that is pocked with more craters. There are also few of the “mare” – dark basaltic “seas” created by lava flows – that are evident on the near side.
The powerful impact that created the South Pole Aitken Basin may have punched through the crust down to the Moon’s mantle layer. Chang’e-4’s instruments could examine whether this was the case, shedding light on the early history of our only natural satellite.
The mission will also characterise the “radio environment” on the