Question

Calculate the distance from the center of the Sun to the center of the Earth when the Earth is at perihelion (q) and aphelion (Q) of its orbit, given that the eccentricity is 0.017. Express the results in kilometers.

Answer 1

Average distance between the Sun at the Earth: a = 149.6 × 10⁶ km

Eccentricity e =  f/a ∴ f = e x a

f = 0.0017 × 149.6 × 10⁶ = 2.54 × 10⁶ km  

At perihelion: q = a - f = (149.6 - 2.54) × 10⁶ = 147.06 × 10⁶ km

At aphelion: Q = a + f = (149.6 + 2.54) × 10⁶ = 152.14 × 10⁶ km