Solar Arc Directions

What it is

Solar Arc Directions advance every natal point — planets, angles, sensitive points — by the same arc. That arc equals the Sun's progressed motion from birth to the chosen target year, which is roughly 1° per year of life.

Unlike secondary progressions (where each planet progresses at its own speed), solar arc treats the whole chart as a rigid wheel that rotates 1° forward per year. This makes activations very clean:

A point that was 7° away from a natal aspect at birth becomes exact when the native is ~7 years old
A point 30° away activates around age ~30

How to find it

Hamburger → WESTERN → Solar Arc Directions. Pick a target year; the panel shows the arc for that year and each natal point's directed position.

How to read

For each planet:

Natal lon — original longitude
Directed lon — natal + arc
Sign — what sign the directed point now sits in

Activations occur when a directed point hits a natal aspect within a tight orb (typically 30 arc-minutes ≈ 6 months). Read the activations as life-events:

Directed Sun conjunct natal Mars → year of action, conflict, or athletic engagement
Directed Mars conjunct natal Saturn → year of structural friction
Directed Venus conjunct natal Asc → year of relational beautification, new partner

The Asc and MC are the most-active angles for solar-arc work. Directed Asc / MC into a new sign is a common timing-marker for life-direction shifts.

Why this works

The Sun's progressed motion is the heartbeat of the chart's forward motion in the secondary system. Solar arc takes that heartbeat and applies it to everything. Practically, this means:

Aspects between directed and natal points fire once per ~30-60 years for most planet-pairs
Each fire is a meaningful life-event signature

Pairing with other layers

Solar arc + transits + progressions = the 3-fold predictive combo in modern Western practice:

Transit — when a current planet hits a natal point
Progression — when a slow-moving inner-life point hits
Solar arc — when the whole chart rotates a directed point onto a natal aspect

When all three converge on the same year, expect a major event.

Caveats

Tropical positions used. Sidereal users will need to interpret the directed sign in their preferred zodiac.
The arc value here is computed by progressed-Sun motion; alternative Naibod arc (a fixed 0°59'08" per year) will give slightly different values for non-Sun-anchored chart-types. KarmaWheel uses progressed-Sun arc by default, which is the modern standard.

Sources

Frank Naibod, De Subtilitate (1556) — the original Naibod arc
Charles Carter, Symbolic Directions in Modern Astrology (1929)
Reinhold Ebertin's Cosmobiology — emphasises solar arc + midpoints