A Modern Planet

Pluto was long counted the ninth planet and is treated in modern astrology as an outer body associated with Scorpio and with themes of depth and transformation. In 2006 it was reclassified by astronomers as a dwarf planet, a change astrology has not followed. Its name, like its glyph, was chosen quickly after discovery: an eleven-year-old English schoolgirl, Venetia Burney, is credited with first suggesting Pluto, for the Roman god of the underworld, and the name was adopted within months, a far faster process than the drawn-out naming dispute that had followed Neptune's discovery eight decades earlier.

The glyph settled almost as quickly, built directly from the new name rather than from any classical precedent, since no ancient tradition had a sign waiting to be revived for a body unknown to antiquity. Astrologers have generally treated the 2006 astronomical reclassification as a matter for astronomers rather than for practice, continuing to track Pluto's position and assign it the same interpretive weight it carried while still formally a planet, a divergence that mirrors how earlier reclassifications, such as the nineteenth-century demotion of Ceres from planet to asteroid, likewise left astrological usage largely unaffected even as astronomical categories shifted underneath it.