Classical Astrology · Doctrine of Motion

Planetary Speed Reference

Swift, slow, stationary, retrograde — a classical reference table of daily motion for the seven traditional planets, the lunar nodes and the outer planets, based on Lilly and Bonatti's thresholds.

Why Speed Matters in Classical Astrology

A planet's daily motion (mean motion) is the angular distance it covers along the zodiac in a single day. This speed is not constant; as the planet approaches the Earth in its orbit it accelerates, as it recedes it slows, and at the end of the cycle it briefly stops (stations) and appears to move backward (retrograde).

William Lilly, in Christian Astrology (1647), defines a planet moving faster than its mean as swift in motion; such a planet carries a quick, lively force that accelerates the timing of events. By contrast, a planet that is slow in motion — especially near a station — brings delay, heaviness and "stuckness." Guido Bonatti, in Liber Astronomiae, counts speed as one of the planet's fortitudes.

This page has two parts: first the classical reference table, then a small calculator that gives daily motion from today's and yesterday's degree. Both are used in horary (questions) and electional (timing) astrology.

Part A · Classical Speed Reference Table

Daily motion for the seven classical planets, lunar nodes, and outer planets

Swift threshold Mean (average) Stationary Retrograde
Planet Mean / Day Max / Day Min (Stationary) Retrograde Frequency "Swift" Threshold (Lilly)
☽Moon 13°10' 15°30' 11°50' Never retrograde > 13°10'/day
☉Sun 0°59' 1°01' 0°57' Never retrograde > 0°59'/day
☿Mercury 1°23' 2°12' 0° (station) ~3×/year, ~24 days each > 1°/day
♀Venus 1°12' 1°15' 0° (station) every ~19 months, ~42 days > 1°/day
♂Mars 0°31' 0°48' 0° (station) every ~26 months, ~72 days > 31'/day
♃Jupiter 0°05' 0°14' 0° (station) every year, ~120 days > 8-10'/day
♄Saturn 0°02' 0°08' 0° (station) every year, ~140 days > 4'/day
☊North Node -0°03' -0°03' — always retrograde (mean) —
♅Uranus 0°00.7' 0°04' 0° (station) every year, ~155 days (non-classical)
♆Neptune 0°00.4' 0°03' 0° (station) every year, ~158 days (non-classical)
♇Pluto 0°00.3' 0°02' 0° (station) every year, ~160 days (non-classical)

Part B · Daily Speed Calculator

Enter today's and yesterday's planetary degree from an ephemeris; receive the daily motion and a classical swift/slow classification.

Which planet are you evaluating?
Degrees within sign (0–30) or 0–360 ecliptic
Yesterday's degree, same coordinate system

Classical Use Notes

Horary (questions): Lilly, in Christian Astrology I.81, says that if the significator of the matter is swift, the event happens quickly; if slow, it shows delay. A planet near station is a "stuck" matter; retrograde points to reversal, returning, or cancellation.

Electional (timing): For a meaningful beginning (marriage, business, travel) the planet that signifies the matter should ideally be swift in motion at the chosen moment. The Moon is especially important: a swift Moon applying by conjunction to a benefic indicates that the goal will unfold smoothly.

Profections and transit timing: The transit speed of the annual profection lord sets the tempo of that year's events. A swift time lord brings an intense, fast-moving year; a slow or retrograde time lord points to a year of inner work and delay.

Practical rule: Read the planet's daily motion from an ephemeris and compare it to the mean in the table. Above the mean is swift; below it is slow. Within a ±5-day window of an exact station, the planet is effectively stationary; classically this signals a strong but immobile temperament — "unable to decide."

Primary and Secondary Sources

  • William Lilly, Christian Astrology Vol. I, chapters 23 and 81 (London, 1647) — definition of swift in motion and horary use.
  • Guido Bonatti, Liber Astronomiae Tractatus III (13th c.) — speed as a planetary fortitude.
  • Ptolemy, Almagest Books IX–XIII (2nd c. CE) — calculation of maximum and minimum planetary speeds.
  • Vettius Valens, Anthologies Book II (2nd c. CE) — planetary phases and motion.
  • Brennan, C. Hellenistic Astrology: The Study of Fate and Fortune, Amor Fati, 2017 — chapter on planetary phases.
  • Hand, R. Horary Astrology Rediscovered, Whitford, 2007 — modern application of speed in horary.

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Frequently Asked Questions

About the classical doctrine of planetary speed

Why does planetary speed matter?

In classical astrology, speed is one of the five or six core fortitudes — measurable strengths — of a planet. Lilly says a swift planet accelerates the timing of an event; a slow planet brings delay. In horary, the speed of the question's significator directly affects how quickly the outcome arrives. In electional work, the significator of the chosen moment ideally moves swiftly; otherwise the venture moves at a slow, "stuck" tempo.

What does "swift" mean?

A planet is swift in motion when it moves faster than its own mean daily motion. Lilly gives these thresholds in Christian Astrology I.27: Moon > 13°10'/day, Mars > 31'/day, Jupiter > 8–10'/day, Saturn > 4'/day. For Mercury and Venus the practical threshold is 1°/day, though it varies with elongation from the Sun. A swift planet adds a lively, animating, generally fortunate impulse.

What is a station (stationary planet)?

A station is the brief window in which a planet's speed drops to zero. It happens at the turn from direct to retrograde motion (station retrograde) and again from retrograde back to direct (station direct). In classical sources a stationary planet is "strong but immobile" — an undecided, suspended quality. In horary it signals that the awaited event is on hold. Within a ±5-day window of an exact station the planet is practically still considered stationary.

How was mean motion determined?

Mean daily motion is found by dividing 360° by the time the planet takes to complete one full zodiacal cycle. Ptolemy worked this out geometrically in the Almagest; medieval Arabic astronomers (al-Battani, al-Sufi) refined the tables. Modern values come from Keplerian orbit theory plus JPL DE441 ephemeris data, and they agree closely with the classical means. The values in this table are astronomical standards and are the same in Lilly, Bonatti or any modern ephemeris software.

How does classical astrology use a modern ephemeris?

For a classical astrologer an ephemeris is just raw data. The correct use: read the planet's today and yesterday positions from the daily ephemeris, take the difference, compare against the mean in the table. If the difference is larger than the mean it is swift, smaller it is slow; close to zero or changing sign indicates station or the start of retrograde. Modern ephemerides (Solar Fire, Astrodienst, JPL Horizons) supply the data; the interpretation comes from Lilly, Bonatti and the Hellenistic texts.

Why does the Moon's speed vary so much?

The Moon's orbit is markedly elliptical: at perigee (closest to Earth) it speeds up dramatically, at apogee (farthest) it slows. Daily motion oscillates between 11°50' and 15°30' — about a 30% swing, more than any other classical planet. Lilly treats a fast Moon (especially above 13°10'/day) as a favourable sign in horary: the event arrives quickly and the outcome flows. Bonatti also notes the haste of decisions made near perigee. This is why the Moon is the central planet of classical electional astrology.