Which of the following statements correctly describes why Copernicus decided that the orbits of Mercury and Venus were smaller than the orbit of Earth?
A) Both planets show a complete cycle of phases,like the Moon.
B) Both planets can sometimes be seen high in our sky at midnight.
C) Both planets occasionally pass through conjunction with the Sun,as seen from Earth.
D) Both planets stay fairly close to the Sun in our sky.

Question

Quizplus · Accepted Answer

Copernicus used the principle of homocentric spheres to model the universe, which assumes that each planet is carried on a crystal sphere that rotates around the Earth. However, he noticed that the orbits of Mercury and Venus seemed to be inside the orbit of the Sun as seen from Earth, meaning that they must stay fairly close to the Sun in our sky. Therefore, he concluded that their orbits were smaller than Earth's orbit.

Which of the Following Statements Correctly Describes Why Copernicus Decided