Is there a place on Moon (sure it's near north or south pole) that is always lit by sun? It's to install solar panels if I will choose to make rancho there :)

What diameter of Moon Polar circle? How high the hill or mast on the pole should be to be always lit?

I used some online calculators and found next:

Axial tilt to ecliptic is 1.5424°, Lunar Radius 1738km

Polar circle is 46.8km

Spherical cap height 0.15km

Are my calculations correct? It shows that it should be near 150 meters high. Is any high enough hill exists on a poles?

P.S. Where I can check good 3d model of Moon with elevation (sure there is no sea level but ideal sphere)?


  • $\begingroup$ One nit: clearly nowhere on the moon can receive light from the sun during a lunar eclipse. $\endgroup$ Commented Apr 30, 2018 at 17:42
  • $\begingroup$ @CarlWitthoft Not so clearly: even when the Moon is fully within the umbra of a total lunar eclipse, it still receives some sunlight refracted through Earth’s atmosphere. Hence the “blood moon”. $\endgroup$ Commented May 1, 2018 at 8:36
  • $\begingroup$ @Chappo well, yeah, and then I could point out that the moon receives a couple hundred photons/second of sunlight reflected back off Mars :-) $\endgroup$ Commented May 1, 2018 at 11:45
  • 1
    $\begingroup$ @CarlWitthoft agreed, and we can also see the new moon dimly due to reflection of galactic light (and probably some re-reflected sunlight from Earth). But my point is that if you're going to nit-pick with the emphasis on your correction being clearly obvious, accuracy becomes important. While the Moon appears much dimmer during a lunar eclipse, the amount of direct (penumbra) and refracted (umbra) sunlight it receives is still substantial, and orders of magnitude more than any reflected sunlight from Mars. $\endgroup$ Commented May 2, 2018 at 2:49
  • $\begingroup$ Mare Vaporum sounds pretty lit. $\endgroup$ Commented Nov 11, 2023 at 1:20

1 Answer 1


This kind of location is called a peak of eternal light.

Apparently there is no certain identification of such a peak on the Moon, but there are definitely places that get more than 86% sunlight during the lunar year (ignoring eclipses). Kaguya did not find any permanent peaks, but there is apeak near Peary at the North Pole that gets 89%, and several places near the South Pole that have multi-month illumination.

Calculating the requirements for such a peak is complicated since the moon is definitely not spherical on the hundreds of meter scale; at the very least one needs an ellipsoid model. The south pole situation is complicated because there is a large basin around the actual pole.


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