Step I Pre-reading

Talk about the center of the solar system.

“Do you know what is the center of the solar system?” Ask the students to look at the pictures on pages 7. And remind them of the common knowledge of “Sun-Centered Theory”.

Talk about Copernicus .

We know the first scientist is Copernicus. He was one of the first scientists to use mathematical observations to collect information. He believed the sun is the center of the universe and the earth and other planets went around it.