As far as I understand it, the equation of Jupiter the planet with Jupiter the god is not of Indo-European date or origin, but is a much later adaptation of an oriental / Babylonian system. So Jupiter / Zeus was originally the god of the bright day and the father of gods, and later was assigned to the planet Jupiter because his Babylonian equivalent (Marduk, the chief of gods) had been (see the wikipedia article at
http://en.wikipedia.org/wiki/Planet for details). At this point of time the theonym Jupiter / Zeus had already become etymologically opaque (i.e., Romans and Greeks didn't know that the theonym originally had meant "shining, bright"), so there is no need for Jupiter being the brightest planet.
Best regards,
Hans-Werner
--- In cybalist@yahoogroups.com, "megalith6" <megalith6@...> wrote:
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> Sorry Piotr, I missed your initial answer. I have a problem here. Since the root of *dyeus is *djeu- 'shine' the IE word which gives us the French <<dieu>> 'god', <<jour>> 'day' and 'Jupiter' which is the same in French and English, where did the connection between 'shine' and 'day' come in? Jupiter shines brightly and has long been seen as 'king of the gods' in IE mythologies, but if stellar brightness was a qualification for providing the light of day then a prime contender for that role would surely have gone to Venus?
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> Ric (perplexed)