# What is the “lunar irradiance” received by the Earth from the full Moon?

The solar irradiance received by the Earth is 1361 $$W/m^2$$. What is the lunar irradiance received by Earth from the full Moon in the same units? My first thought was to work it out via apparent magnitude but I don't think that would work out.

• It works out. A difference of 14 magnitudes is a factor of 398,000. – Mike G Aug 30 '20 at 20:00
• The Earth-Moon distance of course varies by about 15%, meaning that the luminosity varies by about 30%. – ProfRob Aug 31 '20 at 7:58
• Technically :-), you could calculate it based on the sum of two things. 1) solar irradiance on the moon combined with the moon's reflectivity and BRDF, and 2) the same but for irradiance at the moon caused by Earth-based light sources. – Carl Witthoft Aug 31 '20 at 13:05