But wait, it gets better! According to Wikipedia:
So the first syllable in the name Jupiter is basically equivalent to Zeus, but the same word was transcribed/transliterated differently by two different cultures.Zeus is the Greek continuation of *Di̯ēus, the name of the Proto-Indo-European god of the daytime sky, also called *Dyeus ph2tēr ("Sky Father"). The god is known under this name in the Rigveda (Vedic Sanskrit Dyaus/Dyaus Pita), Latin (compare Jupiter, from Iuppiter, deriving from the Proto-Indo-European vocative *dyeu-ph2tēr), deriving from the root *dyeu- ("to shine", and in its many derivatives, "sky, heaven, god").