In the greek geocentric model, the retrograde motion of a planet occurs when: earth is about to pass the planet in its orbit around the sun. the planet actually goes backward in its orbit around earth. the planet is aligned with the moon in our sky.

This is a 2017 topographic map of puerto rico in the united states, and i'm sorry that people there have suffered such a disaster. i want to ask, what do the yellow dots and areas represent on this graph? and the blue area and the little blue circle, and the little blue sign that looks like a signal tower, what do they stand for?