The Earth and the Moon have been neighbors for a very long time. We should expect long term steady state heat transfer from Earth’s internal energy (without Sun) to the Moon to be equal to Earth’s geothermal heat flux. To my knowledge, no one has ever made this claim. Sound outrageous? Let’s see…
According to [Davies 2010], the geothermal flux is 46.7 TW:
We conclude by discussing our preferred estimate of 47 TW, (rounded from 46.7 TW given that our error estimate is ± 2 TW)— [Davies 2010]
When we divide this figure by the surface area of the Earth, we get:
(46700000000000 ± 2000000000000)/510065728777855 = 0.09155683 ± 0.0039 W/m²
This is not an emergent radiative flux, but a conductive heat flux.
I will now argue that this number is not accidental, but is based on heat transfer from the Earth to the Moon.
In my article Measuring Geothermal …, I extracted 335.643 W/m² as an emergent flux equivalent from geothermal.
In my article Deducing Geothermal, I deduced 332.46 W/m² as an emergent flux equivalent from geothermal.
Let’s average those two values to get: 334.05 W/m²
Now we apply the inverse square law for distant radiation, using data from NASA:
334.05 W/m² × (6371 km/ 378000 km)² = 0.09489495 W/m²
This value falls within the error range of measured geothermal flux. Do you think this is a coincidence? I think not. It makes perfect sense.
Enjoy 🙂 -Zoe