No wind blows and no rain falls there. Only crashing meteorites occasionally disrupt the stillness. The desolate landscape on the moon’s far side has waited billions of years to see the first-ever soft landing of a visitor from the earth – Chang’e-4 from China.
As the nearest heavenly body, the moon has fascinated humankind since we first gazed at the sky. The silver disc in the sky is always a captivating theme in our legends, myths, and dreams. Its ever-changing face has inspired ambitious aspirations. We admire its beauty from the earth, so why are we so eager to reach the moon? It’s an ideal place to peer into the deep reaches of the universe. It inspires our imaginations and dreams of space travel.
The moon and the earth share a similar “childhood”, yet traces of the remote past on earth have been erased by geological activities. Exploration of the moon might provide some insights into the early history of the earth. But due to the tidal locking effect, we only get to see one side of the moon from the earth, and the far side remains a mystery. It’s also called the dark side, although it’s not darker than the near side. The word dark only shows how we feel about the unknown.
Nobody had ever seen the moon’s far side before the Soviet Union launched the Luna 3 probe in 1959. It was the first-ever mission to photograph the far side. The United States Apollo 8 mission sent three astronauts around the moon in 1968, the first time humans saw the moon’s far side with their own eyes. Now China sent the first-ever probe to soft-land and rove on the far side, which has deepened our understanding of the moon, the earth, and the universe.
Between the 1950s and 1970s, the United States and the Soviet Union raced against each other in early lunar exploration. After a lull, new interest was triggered in the 1990s when scientists found there might be water on the moon. Since the turn of the millennium, more countries such as China, Japan, and India have joined the lunar exploration club. To date, the world has launched over 100 manned or unmanned missions to the moon.
Flying to the moon has been a dream of the Chinese since ancient times. The moon has long been a major theme in Chinese poems, music, and paintings, with artists and writers using the moon to express their emotions and thoughts about the universe. Since the 1990s, Chinese scientists and engineers have endeavored to make the dream a reality. China announced in 2000 that its space planning agenda contained preparatory research about lunar exploration. It officially began the lunar exploration program in 2004, with the aim of orbiting and landing on the moon, and bringing samples back to the earth. The program was named after the moon goddess Chang’e, who, in Chinese mythology, lived on the moon and was accompanied by the Jade Rabbit.
Although China is a latecomer in lunar exploration, its program has made many achievements in a few expeditions. The country verified its lunar probe technologies in 2007 with the successful launch of Chang’e-1, the first spacecraft stemming from the program. In 2013 Chang’e-3 accomplished China’s first soft-landing on the moon, which was the first man-made craft to achieve this goal in nearly four decades.
After Chang’e-3’s accomplishment, Chinese space experts aimed high to make the Chang’e-4 mission more innovative and challenging: to realize the first-ever soft-landing on the far side of the moon. In order to achieve that goal, China launched a relay satellite, named Queqiao (Magpie Bridge) after an ancient legend, to set up a communication link between the earth and the moon’s far side. Chinese space experts also overcame difficulties with the rugged terrain on the far side, making the probe land on the moon with high precision.
The Chang’e-4 mission carried instruments that had been developed by scientists from Sweden, Germany, the Netherlands, and Saudi Arabia, providing more opportunities for the world’s scientists and combining human wisdom to explore the universe. Now China is drawing up plans to explore the moon’s polar regions and inviting other countries to join in further expeditions. “I think one of the beauties of space science is that we do cooperate internationally. Space science to me is something important, also as a message of peace worldwide,” said a German professor in the program.
The probe took some live species like cotton and potato to the lifeless environment to form a mini biosphere, which is expected to produce the first flower on the moon. Engineers also plan to get data by constantly measuring temperatures on the surface of the moon.
From robotic to manned missions, from short- to long-term, China’s lunar exploration will go deeper. The Chinese will leave their footprints on the surface of the moon in the foreseeable future.
Exploring the moon has inspired scientists and engineers, fascinated young and old, and motivated young people to pursue scientific careers, not only in space but also in the depths of the ocean or in the nucleus of an atom. Reaching the moon, the first outpost in deep space, is just the beginning of our space odyssey.