Question

For simplicity, let's assume that the solar flux at the moon's distance from the sun is the same as the solar flux at Earth's distance from the sun. a) Given that the moon has virtually no atmosphere and 'moonlight' is solar flux reflected by the moon, determine the average intensity of 'moonlight' immediately above the illuminated hemisphere of the moon. Assume that 'moonlight' is evenly reflected from the entire illuminated hemisphere of the moon. Provide an expression and solve.

Answer 1

The average intensity of 'moonlight' immediately above the illuminated hemisphere of the moon is 156 W/m², reflecting 12% of the 1.30 kW/m² solar flux received from the sun.

Step-by-step explanation:

To determine the average intensity of 'moonlight' immediately above the illuminated hemisphere of the moon, the solar flux at Earth's distance from the sun, which is the same at the moon's distance, is taken as 1.30 kW/m².

Given the moon's albedo, or reflectivity, is approximately 0.12 (12%), the solar flux reflected by the moon is 0.12 × 1300 W/m² = 156 W/m².

So, the average intensity of moonlight just above the moon would be 156 W/m² assuming an even reflection from the entire illuminated hemisphere.