Mathematical Proof of the Mars Rumor

The Red Planet Mars
We are now going to prove why Mars cannot appear as big as the full moon in the night sky, EVER. We are going to use the following known properties:


Distance of the Moon from the Earth: Approx. 3.84*10^9 m
Distance of Mars from the Earth: Nearest Possible Approx.: 7.5*10^10 m<!–[if gte msEquation 12]>7.5×1010m<![endif]–>
Diameter of the Moon: 3.47*10^6 m<!–[if gte msEquation 12]>3.47×106m<![endif]–>

Diameter of Mars: 6.68*10^6 m 

The Moon
Now, we need to compare the sizes of the two objects in our night sky, which is also called the Apparent Size. Luckily, we have a mathematical relationship for the same: 

Apparent Size (in degrees) = 360 degrees*Diameter of the object/2*π *Distance from the object

Substituting known values of the moon, 

Apparent size= 360*3.47*10^6/2*π *3.84*10^8= approx. 0.5 degrees 

Substituting known values for Mars, 

Apparent size= 360*6.68*10^6/2*π *7.5*10^10= approx. 0.005 degrees 

Comparing Apparent sizes, 

Apparent size of Moon/ Apparent size of Mars= 0.5/0.005 = 100/1 

Thus, the full moon is a 100 times bigger than Mars in the night sky even when Mars is at its closest point to the Earth. 

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