if we point a laser at the moon

the energy transfer in the air at the same strength, due to the density of the medium.  in vacuum 1/rr. f=Ke x e1e2/rr.

to detect laser reflects from the moon seems impossible, the light will be so weak, and it should be almost instant.

light transmission in space is instant, strength decay at 1/rr.

sunlight is a giant multi color laser beam, the distance from the sun makes the beam strength decay at 1/rr. if air between sun and earth, we will be way hotter than the sun, cuz the beam is concentrated.