Some scientists were working in a spaceship in outer space. The scientists looked out of the window. They could see the planet Earth. It looked like a blue and white ball.
Now we have many photos of our planet from outer space. Some scientists used very powerful cameras. The photos were very clear. The scientists were surprised at what they saw. What did they see? Can you guess?
In the photos, they saw land, blue sea and white clouds. Some scientists said they could see a long, dark line on the yellow earth. They thought it was the Great Wall of China! Do you think so?
