On the moon, even day kind of looks like night.  And for similar reasons, shadows look very weird.  And you might have noticed that in pictures from the Apollo missions, the sky on the moon, even in the daytime, is black.  That is because there's no atmosphere there to scatter the light around.  And that's exactly what it sounds like, photons of light hit molecules and particles in the air and they bounce around.  And on the earth, after that bouncing, mostly blue light is what hits our eyes.  It's why the sky looks blue.  But not on the moon because there's no atmosphere. But that also means that shadows are super dark.  Think about your shadow here on earth.  Like, it's darker, like it's a darker patch, but you can still see what's there.  But moon shadows are nearly pitch black, and it is for the same reason.  The atmosphere on earth scatters light around, so even if you're facing away from the light source, there's still some light there being bounced from other points in the sky.  But with very, very little light scattering on the moon, there is no way to see into the shadows.