What better way to celebrate 50 years since the Apollo 11 landing than going back to the Moon? But this time there will be no humans setting foot on the Moon. Instead, two robotic missions will explore the unchartered southern lunar hemisphere, sending back a wealth of information about the surface and composition of the Moon, and perhaps even more.
Early December last year, the China National Space Administration Chang’e 4 mission launched, set to land in the Von Kármán crater in the South Pole–Aitken Basin on the far side of the Moon. This is the first landing on the far side of the Moon and the targeted region is the largest known impact crater in the Solar System. The rover is equipped with various instruments to investigate the lunar morphology and subsurface. In addition, it will carry a tin with air, water, soil and seeds to see if they will grow in the harsh environment. In order for the Chang’e 4 lander and rover to be able to communicate with Earth, last year a relay satellite named Queqiao was put in orbit around the Lagrange Point 2, a gravitationally stable spot beyond the Moon.
Chang’e 4’s mission aims higher than the Moon. It also carries the Netherlands–China Low-Frequency Explorer, which will listen for whispers from the early Universe. Taking advantage of the radio silence on the far side, where the Earth’s electromagnetic noise does not reach, the instrument will attempt to detect the faint signal emitted a few hundred million years after the Big Bang by the hydrogen gas in the earliest stars.
Scheduled to launch this month, the Indian Space Research Organisation’s Chandrayaan-2 mission is expected to be the first to land near the south pole. The mission includes an orbiter, a lander and a rover. Most data will be gathered during the daylight, lasting for 14 Earth days, as the lander and rover are not expected to survive the long night. The spectrometers, cameras and seismometer will gather information about the lunar geology and composition, the charged particles in its thin atmosphere and, perhaps most excitingly, about the amount of water on the Moon.