Pluto

Meaning

Pluto, found in 1930 and reclassified as a dwarf planet in 2006, is still counted by astrologers among their ten planets. Its orbit is long and stretched: it takes about 248 years to go round the zodiac, crossing some signs in about twelve years and others in more than thirty, and it is retrograde for about five months a year.

Astrologers read it as power, intensity and deep change: what lies hidden, what has to end, and what is rebuilt from the ground up. It describes where someone meets the strongest forces of life, within or around them, and where they are asked to let go and be remade.

Its sign marks a generation; its house and its contacts with the personal planets and the angles carry the personal meaning. Modern astrologers make it the ruler of Scorpio beside Mars, the sign’s traditional ruler. Tradition never knew it and gives it no dignity.

Its gifts are depth, resilience, honesty about what is hidden and the capacity for renewal. Its difficulties are control, obsession, struggles for power, and holding on past the time for letting go.

In practice

• Its house shows where life is lived most intensely: in the 8th, shared resources, intimacy and crises; in the 10th, questions of power and authority.
• Close to the Sun, the Moon or an angle, it often marks someone drawn to depth, through research, psychology or crisis work, who guards their private life closely.
• Its transits last two to three years and are associated with change that cannot be undone: ending what no longer works, and rebuilding.
• Its square to its own birth place comes at very different ages from one generation to another, because its speed varies so much along its orbit.

Across traditions

• Traditional astrology, Western, Indian and Chinese, never knew it.
• Chinese now calls it 冥王星 Míngwángxīng, the star of the King of the Underworld, after its Western name.
• Human Design counts it among its thirteen bodies: Pluto is truth, its gate showing where slow, deep change happens and what cannot stay hidden.

Origin and history

Percival Lowell spent years searching for a planet beyond Neptune. At the observatory he had founded in Flagstaff, Arizona, Clyde Tombaugh found Pluto on 18 February 1930, comparing photographs taken a few nights apart. Its name, after the Roman god of the underworld, was suggested by Venetia Burney, an eleven-year-old in Oxford; its first two letters are also Lowell’s initials, which the glyph ♇ joins. As more bodies were found beyond Neptune, Eris among them, the International Astronomical Union defined the word planet in 2006, and Pluto became a dwarf planet; the New Horizons probe flew past it in 2015. Astrologers took it up in the 1930s and most came to give it Scorpio, and in 1985 Jeffrey Wolf Green built an evolutionary astrology around it. The element plutonium is named after it.

How Ulune calculates it

Ulune takes Pluto from the Swiss Ephemeris (DE441): its apparent position seen from the centre of the Earth, in the tropical zodiac. It is marked retrograde when its daily motion runs backwards and stationary within about seven days of a station.

Ulune’s dignity tables keep to the seven traditional planets, so Pluto has no score; with Scorpio rising, Ulune names it as the modern chart ruler beside Mars. Within 8° of the Sun it is marked combust, as every planet is in Ulune, a notion tradition kept for the visible planets. The calendar dates its stations, sign changes and exact transits, with the whole span each transit stays within a degree.