The geocentric model could not explain which of the following observations made by early astronomers? Select the two correct answers.(1 point)
Responses
Mars and Jupiter appeared to move backwards for some period of time.
Mars and Jupiter appeared to move backwards for some period of time.
The stars appeared to move.
The stars appeared to move.
Mercury and Venus changed in appearance throughout the year.
Mercury and Venus changed in appearance throughout the year.
The planets had epicycles.
The correct answers are:
1. Mars and Jupiter appeared to move backwards for some period of time.
2. Mercury and Venus changed in appearance throughout the year.
The geocentric model assumed that all celestial objects, including the planets, revolved around the Earth in perfect circles. However, the observations of Mars and Jupiter moving backwards at certain times (known as retrograde motion) and the changing appearances of Mercury and Venus contradicted this model. These observations could not be explained by the geocentric model, but were later understood and explained by the heliocentric model proposed by Nicolaus Copernicus. The inclusion of epicycles in the model was an attempt to explain the irregular motion of the planets but was not directly related to the geocentric model's inability to explain the listed observations.