In: Physics
(a) Show that the solar flux densities (irradiances) from the sun, F1 and F2, relate one another as the inverse square of their distances from it, that is: 2 2 1 2 1 F = (r /r ) F .
(b) Use the answer to (a) to solve the following question: The orbit of Mars around the sun is more eccentric than that of the earth. At its closest Mars is 200 million kilometers from the sun, and at its furthest it is 250 million kilometers from the sun. Given that the flux density of solar radiation reaching the earth is 1368 W/m2 and the earth-sun distance is 150 million kilometers, estimate the solar flux density impinging upon Mars at its two extreme distances from the sun. What do these numbers tell you about the likely variations in the mean temperature of the surface of Mars during its passage around the sun?