Jupiter vs Jovian

Jupiter is a noun but Jovian is not a noun.

Word	Noun	Adjective	Verb	Adverb
Jupiter	Yes	No	No	No
Jovian	No	Yes	No	No

Jupiter (noun)	Jovian (noun)
the largest planet and the 5th from the sun; has many satellites and is one of the brightest objects in the night sky
(Roman mythology) supreme god of Romans; counterpart of Greek Zeus

Jupiter (adjective)	Jovian (adjective)
	of or pertaining to or befitting the Roman deity Jupiter
	of or pertaining to or characteristic of or resembling the planet Jupiter