Luna's standard portrait in Roman art borrows heavily from the Greek Selene: a crescent moon set like a diadem above the brow, a flowing veil billowing overhead like a canopy of night, and a torch or a pair of torches carried to mark her passage through the dark. She is frequently paired with Sol on the same monument, the two riding in opposite directions across a single relief or flanking a central scene, as on the tauroctony reliefs of the Mithraic mysteries, where Sol and Luna witness the bull-slaying from the upper corners of the composition as the fixed lights of the cosmic order. This visual partnership carried into the calendar itself: the Roman month (mensis) took its rhythm from the moon's phases long after the civil calendar had been reformed to follow the sun, and religious observance was still reckoned partly by lunar markers such as the Kalends, tied historically to the first sighting of the new moon.
Luna also inherited, through her identification with Selene, the Greek story of Endymion, the shepherd she loved and visited nightly as he slept an eternal sleep, a tale later poets folded freely into her Roman persona even though it has no native Latin origin. Her afterlife in language is perhaps her most lasting monument: lunar, lunacy and lunatic all descend from her name, preserving the old belief, never fully abandoned, that the changeable moon could unsettle the changeable mind. In astrology she remains the swiftest moving of the classical lights, completing her circuit of the zodiac in under a month and standing, opposite the Sun, for feeling, habit and the private self rather than for will and identity.