Earlier this year, China achieved a new milestone (里程碑) in space research. On January 3, 2019, Chang'e-4 became the first lunar probe (月球探测器) in history to successfully land on the far side of the moon.
The Earth's gravity (重力) slows the moon's rotation (自转), matching it to the speed of its orbit (公转). Therefore, the far side of the moon is almost "dark" and has never been seen. It's this sense of the unknown that makes the far side of the moon such an interesting place for scientific and space research. Being blown by solar (太阳的) winds, the far side may have the special minerals (矿物质). For this reason, Chang'e-4 will study the effect of solar winds on the lunar surface and any mineral found by the spacecraft. Chang'e-4 is also carrying flower seeds, potatoes and silkworm eggs to see whether life is possible on the moon. If it is, then the moon will become a possible choice for space travel in the future.
However, research of the "dark" side isn't easy. As the far side is blocked(阻断) off from us, radio noise coming off Earth is also blocked. This is why China's relay satellite (中继卫星) Queqiao was sent up in May, 2018. Thanks to Queqiao, the communication problem between
Earth and Chang'e-4 has been well solved.
Power supply (电源供应) is also a challenge to the task. Chang'e-4 gets energy from the sun through its solar panels. As we know, a lunar day has the length (长度) of 28 Earth days. After Chang'e-4 was sent up on December 8, 2018, it took the probe over 20 days to orbit the moon to be in a position to be able to land in moon daylight and use its solar panels.
Luckily, everything goes well, Chang'e-4 has worked on the "dark" side for over 5 months. It has sent back many photos of the far side of the moon and has been used to carry out some scientific experiments.
The New York Timesused the word "groundbreaking" to praise the task and wrote that "it will offer help to the history and development of the moon".
