Consider again the set of observations from Part A. This time, classify each observation according to whether it is consistent with only the Earth-centered model, only the Sun-centered model, both models, or neither model. (Note that an observation is "consistent" with a model if that model offers a simple explanation for the observation.)
(1) Mercury goes through a full cycle of phases.
(2) Moon rises in east, sets in west.
(3) stars circle daily around north or south celestial pole.
(4) positions of nearby stars shift slightly back & forth each year.
(5) a distant galaxy rises in east, sets in west each day.
(6) a planet beyond Saturn rises in west, sets in east.
(7) we sometimes see a crescent Jupiter.

Mercury goes through a full cycle phase. This is not sun-centered because the earth rotes from west to east,therefore objects in the sky moves east to west.

We sometimes see a crescent in Jupiter . These models cannot classify the observation because for an object to be seen as a crescent,the object must come between the earth and the sun.

Observation 3 and 5 can be classified with both models because the rise and set of all objects in the sky depend only on the rotation of the earth.