Planetary

google

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late 16th century: from late Latin planetarius ‘relating to the planets’ (recorded only as a noun meaning ‘astrologer’), from planeta ‘planet’.

wiktionary

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planet +‎  -ary

etymonline

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planetary (adj.)

1590s, "of or pertaining to a planet;" see planet + -ary. Perhaps from or based on Late Latin planetarius "pertaining to a planet or planets," but according to OED this is attested only as a noun meaning "an astrologer." Planetary nebula, so called for its shape as seen through a telescope, attested from 1785.