When you want to forecast events, or get a deeper understanding of a past event, you will usually look up transits of the planets Jupiter through Pluto, especially to the angles, Sun, or Moon. However, if you only look at transits, you will sell yourself short. There is another measurement that is equally important, and that is the solar arc, or more formally, solar arc directions. In order to understand solar arc directions, we first need to understand secondary progressions. A secondary progression is a symbolic movement applied to a planet, in contrast to the “real” movement that is a transit.
Say a person (Jane Doe?) was born on June 1, 1980 at midnight UT. Exactly 24 hours later, at noon on June 2, 1980, all the planets would have transited to new positions according to how much they advanced (or retrograded) in that time. These transit positions are taken to be equal to the secondary progressed (SP) positions of the planets for June 1, 1981, exactly a year after birth. Here’s the ephemeris for the first 5 days of June, 1980, to illustrate:
So for this person, the SP positions of planets exactly a year later (June 1, 1981) would be equal to the actual positions (transiting) of planets on June 2, 1980. And the SP positions two years later (June 1, 1982) would be the same as the actual positions on June 3, 1980.
Thus, SP symbolically equates a day’s worth of motion of each planet to a year in the life, and is used to forecast the year-to-year unfolding of the life. The SP position of the Moon is the most useful of the lot since it moves the most during a day. So, here, 2 years into the life, SP Moon has changed signs from Capricorn to Aquarius. On the other hand, the outer planets move very little daily, so their SP positions even years from birth would hardly be different than the birth position.
And in this example, since Uranus, Neptune, and Pluto are all retrograde, their SP positions are actually going backward year to year. So the “progression” is reversed. This is actually an interesting developmental phenomenon in the life, particularly when applied to the faster planets such as Mercury, Venus, and Mars. Aside from this outlier that does merit attention, secondary progressions are generally not very useful in timing the impact of events. However solar arcs most definitely matter, for all planets.
So, what does a solar arc (SA) have to do with a secondary progression (SP)? SP gave rise to the concept of of a “day for a year.” The Sun, which has always been given pride of place in Western astrology, moves about a degree a day. Why not use the motion of the Sun, the giver of life, as a symbol for the unfolding of life, and use it to move all other planets at the same rate? This is the concept of the solar arc, the span covered by the Sun in a day, lent to all the other planets so that they are forward directed by the same arc. Hence solar arc direction.
To determine the SA positions, do the following. Start with the longitudinal arc covered by the Sun (SA) in its motion in a single day. Then, advance the Sun, and all the other planets (and the nodes, and the angles) by this solar arc. These new positions are the SA directed positions that would equate to one year in the life. Since all the bodies in the horoscope will be advanced by the same arc, they are accorded equal importance. Moreover, none of the bodies ever moves backward since the Sun is never retrograde. The outer planets, in particular, now become remarkably prescient indicators of life transformations.
Following is the natal chart of the academy-award winning actor Jodie Foster.
See that Uranus is at 05 Vir 04, Neptune is at 13 Sco 43, and Pluto is at 12 Vir 00. Now eyeball the arc distance between each of these planets and the angle that is nearest to it. For Uranus and Pluto the nearest angle is the MC at 03 Lib 47: the arc distance from Uranus to the MC is 28o43‘, and from Pluto to the MC is 21o47‘. Neptune appears to be right in the middle of the MC to Ascendant span, so we will need to figure out which is closer. The MC-to-Neptune span is 39o56‘ while the Neptune-Ascendant span is 34o13′. So Neptune is closer to the Ascendant by more than 5 degrees.
For purpose of estimation, assume that the arc distance covered by the Sun in a day of motion is exactly one degree. (In reality it varies, covering a little less than 1 degree in the summer, and a little over 1 degree in the winter.) Then, in the SA directed technique, all planets would be advanced by one degree for one year of life. In this example, therefore, SA directed Uranus (written simply as SA Uranus) would come to conjunct the MC in 28 and 43/60 years, or approximately 28 years and 8 months, SA Pluto would conjunct the MC in approximately 21 years and 9 months, and SA Neptune would conjunct the MC in about 34 years and 2 months. (1 degree=60 minutes of arc is= 12 months of SA time, so every 5 minutes=1 month of SA time.)
To delve a little deeper, let’s focus on the SA directed Uranus. Foster was born on November 19, 1962. When she is about 28 years and 8 months of age, SA Uranus would conjunct the natal MC, which would put the date of this event at about July 19, 1991. Let’s draw the SA directed chart for this date, and overlay it on top of the natal chart, much like how we work with transit charts:
The inner ring is the natal chart, and the outer ring shows the SA directed positions of the planets, the nodes, and the angles (A for ascendant and M for MC). SA Uranus is at 04 Lib 08, which puts it 21 minutes of arc past the MC. Now for some fine tuning. The Sun does not move exactly a degree every day. It moves fastest in December, covering a little more than one degree of arc per day. Then, it gradually slows down all the way to June, when it is slowest, covering a little less than one degree of arc per day. Then it gradually speeds up again until it reaches its fastest pace in December.
At Foster’s birth in November, the Sun was close to its highest speed, and so it advanced more than 28 degrees and 43 minutes (arc span from Uranus to MC in the natal chart) in an equivalent number of days (and therefore an equivalent number of SA symbolic years). In other words, the SA directed position of Uranus would have been exactly at the natal MC in less than 28 years and 8 months. In fact, the exact conjunction would have happened around 4 months earlier. Remember that 5 minutes of arc is equivalent to 1 month of SA time, so 21 minutes is about 4 months, which pulls us back from July, to March 1991. What memorable event graced Foster’s life at that time?
Eyeballing SA directions of the outer planets to the angles is a great way to quickly establish the approximate time of important life milestones, the time when some kind of change is likely to make itself felt loud and clear. And it is also fairly easy to adjust for the variable speed of the Sun. If the birth is around December, just subtract a degree from the solar arcs for every 30 years of life, and if the birth is around June, add a degree. Apply proportional corrections to births that are between June and December, or December and June. Another way around is to simply use a year’s window around the estimated date of exact hit. So, in Jodie Foster’s example, you could say that the exact hit happened when she was between 28 and 29 years of age. The vagaries of life will forgive us for not being metronomic!