Middle Age's astronomy.

Copernicus is Holand's natural scientist. He think Sun is center of the solar system. But those days, many people think that Earth is center of the "Earth system". And Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn is orbiting the Earth. Why people think that? Because Ptolemy think that.

 

  But there is a problem. How about Retrogade Motion of Mars?

This image is how ptolemy think about Retrogade Motion of Mars.

 

 Mars has epicycle. It's orbiting the Earth but, it is orbiting the epicycle,too. So Mars can retrogade.


And, Europe's astronomy didn't update. So astronomy's history goes to Middle east Asia.