题目内容：

 

Return to the moon

It might not be long until humans uncover the secrets of the far side of the moon. China’s Chang’e 4 robotic probe (探测器), which is set to become the first probe to land on the moon’s far side, was launched successfully on Dec 8, Xinhua reported.

The moon rotates (自转) at the same speed that it orbits (绕…运行) Earth. Therefore, the same side of the moon always faces Earth. The far side of the moon is the side that we cannot see. We don’t know much about it so far.

However, the far side of the moon is an ideal (理想的) place for scientific research(研究). It is exposed (暴露) to solar winds that may have formed unique minerals (矿物质) and other resources. And since the far side is less affected by Earth’s gravity, scientists can make clearer observations of deep space from there, according to China Daily.

But it is hard to land on the far side of the moon. Spacecraft that land there cannot receive any radio signals(信号) from Earth. To solve this problem, China launched a relay satellite (中继卫星) called Queqiao into space in May. Through Queqiao, scientists can control and operate Chang’e 4 and make sure it will land in a specific(特定的) area.

The probe’s travel time is also important. Chang’e 4 is expected to land on the moon on Jan 2, China Daily reported. It will travel through space for more than 20 days before landing. This is longer than Chang’e 3, which was in space for about 12 days before landing.

The travel time was changed because scientists want Chang’e 4 to land on the moon when it is daytime. This way, the spacecraft’s solar panels ( 太 阳 能 板 ) can receive energy from the sun and allow the probe to start working. A single day on the moon is about 28 days on Earth. Therefore, Chang’e 4 will keep orbiting the moon before landing as it waits for daytime, according to Sun Zezhou, chief designer of Chang’e 4.

Did you know? Chang’e 4 took some plant seeds and eggs to the moon. It was hoped that Chang’e 4 was able to do experiments with them. These were the first biological experiments to take place on the moon.

1.Is Chang’e 4 the first probe to land on the far side of the moon?

2.What does the far side of the moon refer to(指代)?

3.Why does the same side of the moon always face Earth?

4.How did Chinese scientists solve the problem of no signals?

5.Why do scientists want Chang’e 4 to land in daytime?