For the first time ever, there is a spacecraft on the far side of the moon. China recently installed a lander and rover there. The spacecraft is part of the Chang’e (pronounced CHONG-uh) space missions. This series has been named for the Chinese goddess of the moon.
The spacecraft touched down at 9:26 p.m. Eastern time on January 2. A few hours later, a small rover rolled off the craft. Called Yutu 2, or Jade Rabbit 2, it will explore the area around the Von Kármán crater. This site is 186 kilometers (115 miles) wide and is located inside the South Pole-Aitken basin. At 2,500 kilometers (1,553 miles) wide, this basin is one of the largest and oldest impact features in the solar system. It may even contain exposed parts of the moon’s interior. If true, that might reveal details of how the moon formed and what its early history was like.
The landing and other aspects of the mission went without a hitch. The China National Space Administration described this in an online statement.
The mission of Chang’e-4 is to study the moon’s terrain. To do this, the lander will use ground-penetrating radar. It can get information from just below the lunar surface. The rover also will take panoramic images of a landscape that has never been seen from the ground before.
Measurements by the craft could help establish the safety of human travel to the moon. One instrument, for instance, will record charged particles and radiation.
The lander will even test whether plants and insects can grow together on the moon. Apparently, cotton seeds had sprouted. They died shortly afterward, however, during the frigid lunar night.
Getting data back to Earth has been a bit tricky. The moon always shows its same face to Earth. So it is impossible to communicate directly with a spacecraft on the far side. To fix that problem, scientists launched a relay satellite last May. Named Queqiao, or Magpie Bridge, it will beam signals between Chang’e-4 and Earth.
This mission marks China’s second lunar landing. It is a step toward more challenging moon missions. Later this year, China’s space agency plans to send up another craft to collect and bring back samples of moon rock from the moon’s far side.
basin (in geology) A low-lying area, often below sea level. It collects water, which then deposits fine silt and other sediment on its bottom. Because it collects these materials, it’s sometimes referred to as a catchment or a drainage basin.
crater A large, bowl-shaped cavity in the ground or on the surface of a planet or the moon. They are typically caused by an explosion or the impact of a meteorite or other celestial body. Such an impact is sometimes referred to as a cratering event.
ground-penetrating radar A method of detecting the presence, position, distance or other important characteristics of objects (such as rocks or archeological artifacts) or substances (such as water or ice) underground. It works by sending out pulses of electromagnetic radiation that travel through earth and bounce off objects below. Scientists then measure how long it takes that bounced signal to return.
lander A special, small vehicle designed to ferry humans or scientific equipment between a spacecraft and the celestial body they will explore.
lunar Of or relating to Earth’s moon.
moon The natural satellite of any planet.
online (n.) On the internet. (adj.) A term for what can be found or accessed on the internet.
radiation (in physics) One of the three major ways that energy is transferred. (The other two are conduction and convection.) In radiation, electromagnetic waves carry energy from one place to another. Unlike conduction and convection, which need material to help transfer the energy, radiation can transfer energy across empty space.
satellite A moon orbiting a planet or a vehicle or other manufactured object that orbits some celestial body in space.
solar system The eight major planets and their moons in orbit around our sun, together with smaller bodies in the form of dwarf planets, asteroids, meteoroids and comets.
terrain The land in a particular area and whatever covers it. The term might refer to anything from a smooth, flat and dry landscape to a mountainous region covered with boulders, bogs and forest cover.