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Sun Distance Required to Match Apparent Size at Perihelion

-- Bill | July 21, 2025

Question:

I would like to know while standing on the earth’s equator, how far perpendicularly away from the center of two poles that are spaced 30 meters wide I would need to be, so the sun at perihelion is the same 30 meters wide?

-- Bill

Answer:

I believe that you can use the principle of similar triangles to solve this problem. Let D_sun be the diameter of the Sun (1.392×10^9 m), D_poles be the spacing between the poles (30 m) , d_perihelion be the Earth-Sun distance at perihelion (1.471×10^(11) m), and x be the unknown distance to the Sun from the poles. Solve for x:

x = 30m * (1.471×10^(11) m)/(1.392×10^9 m) =~ 3170.26 m

-- Jeff Mangum

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