A student made the following observations about astronomical bodies.

Observation 1: Mars reverses its direction of motion in the night's sky.
Observation 2: The stars move across the sky.

Which observation(s) can be explained using the heliocentric model but not the geocentric model?
Only observation 1
Only observation 2
Both observation 1 and observation 2
Neither observation 1 nor observation 2

Question

A student made the following observations about astronomical bodies.

Observation 1: Mars reverses its direction of motion in the night's sky.
Observation 2: The stars move across the sky.

Which observation(s) can be explained using the heliocentric model but not the geocentric model?
 Only observation 1
 Only observation 2
 Both observation 1 and observation 2
 Neither observation 1 nor observation 2

RawlsK29 · Answer

I put D as my answer and got it wrong, I don't remember there saying anything about Mars reversing its direction in the night sky, and its definitely not B-because that's apart of the geocentric model. @Vocaloid @Bearclaws72 @dude

dude · Answer

Not too sure

@563blackghost can help maybe

RawlsK29 · Answer

@Elsa213

563blackghost · Answer

Mars reversing its motion is entirely by illusion known as retrograde motion.

BUT

Due to Mars having a slower evolution than the Earth (by about .88 earth years) it gives off this illusion due to it ALSO revolving around the sun by the heliocentric model.

That probably is the answer >.>

563blackghost · Answer

though this illusion only takes effect every two years >.>