On December 8 at 2:23 A.M. (BJT), China successfully launched the Chang'e-4 Lunar Probe aboard a Long March 3B rocket. With a lander and rover as a part of its load, Chang'e-4's key mission is to explore the far side of the Moon, a side never visible from Earth.

People have drawn mystery and inspiration from the moon for many millennia, but the reality of this heavenly body are about to get a lot closer. Blasting off from Xichang Satellite Launch Center, China's Chang'e-4 lunar probe could be the first ever to soft-land on the far side of the moon.

The moon's far side is never visible from Earth due to a phenomenon called tidal locking. This means only one side of the orbiting body faces our planet directly. To begin exploring this uncharted area, the first key challenge was to guarantee communication with controllers on Earth. Since the moon itself blocks radio transmission, China launched Chang'e-4's relay satellite, Queqiao or Magpie Bridge earlier this year. It's role is to “bounce” the probe's signal back to Earth. It has since entered Halo orbit around the moon, where it will serve as a perfect communication link.