Chang'e 5 completed its task successfully in 23 days, not only did it return with valuable rock and soil samples from the moon, but also brought back a group of seeds that traveled the furthest in China, including rice, oats etc., were placed inside the Chang'e 5 spacecraft and went around the moon for about 15 days.
Scientists wished to check what would happen to the seeds after the task. This task offered good opportunities to scientists, which helped them to deepen their studies on the effect of cosmic rays(宇宙射线)on the growth and development of life on Earth.
Space-based mutation breeding (太空诱变育种) refers to the process of placing seeds in the environment such as micro gravity (微重力), vacuums (真空) and cosmic radiation (宇宙辐射) during a spaceflight and then sending them back to Earth for further study and planting. Scientists study and examine several generations of plants grown from seeds which went into the space and study their changes-some are desirable while others are bad and negative. Those with good changes will be kept for further research, and will be introduced to farmers after getting permission.
Space breeding(育种)can make the seeds change faster than the experiments on the earth and can bring about some wonderful results. Compared with the traditional methods, space-developed methods can make the seeds grow much better, such as having shorter growth periods and having more power to fight against diseases and insect.
China did its first space breeding experiment in 1987, using a satellite to carry seeds into space. Since then, hundreds of kinds of seeds and seedlings have traveled with dozens of Chinese spaceships. Space breeding has helped to produce more than 200 new types of mutated plants in China that have been allowed to be planted across the country from grains to vegetables and fruits.
The Chang'e 5 brought back 1,731 grams of moon's rock and soil to Earth, showing a historic achievement 44 years after the last moon's rock and soil were taken back.
