 It was the third asteroid found, but was initially considered to be a planet; it was reclassified as an asteroid and minor planet during the 1850s.Juno is named after the mythological Juno, the highest Roman goddess.The adjectival form is Junonian (from Latin "jūnōnius"), with the historical final "n" of the name (still seen in the French form, "Junon") reappearing, analogous to Pluto ~ Plutonian.