Lesser light

1:16 And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also.

 This is more specific than just lights in heaven.  They're not explicitly named here, but it's clearly the sun and the moon.  And the stars are named.

The first point I want to make is this: the moon is radically different from the sun and stars.  The sun and stars are actually light sources; the moon just reflects sunlight.  The moon is technically not a light.

I mentioned before that this tells us something about heaven: it contains the sun, the moon, and the stars.

The most interesting bits here are the new purposes.  The purpose of the sun here is "to rule the day"; the purpose of the moon is "to rule the night".  This is pretty strange if taken literally; it makes the sun and moon sound like kings or gods.  I think this is one of the hints that this story is older than monotheism.

The other thing about this is: the moon isn't always out during the night, and isn't always visible during the night.  It doesn't rule the night the same way the sun rules the day.  And the moon is sometimes visible during the day, although never nearly as bright as the sun.  But, during total solar eclipses, the moon passes in front of the sun, blocking it out.  At that moment, you could say that the moon rules the day.  Ironically, that is also when the sun seems most kingly, as that is when you can most clearly see its crown.

It notable that the only purpose (ruling) given here for the sun and the moon is not even listed among the six purposes previously mentioned for the lights.