Question

025 astronomy fall final exam (1st semester) 34 of 60 if ptolemy’s model of the universe was correct, then venus would always remain between the sun and earth on its epicycle. if this w the case, what is the only phase of venus that an observer from earth would be able to view? (use the gif to help you) © l. perera gibbous quarter crescent full

Explanation:

In Ptolemy's geocentric model, if Venus is always between the Sun and Earth, the illuminated part visible from Earth would be a small crescent - like shape. A gibbous phase would require more of Venus to be illuminated (not possible if it's between Sun and Earth), a quarter phase would imply a different positional relationship, and a full phase would mean Venus is on the opposite side of the Sun from Earth (which contradicts it being between Sun and Earth). So the only phase possible is crescent.

Answer:

Crescent