The natal chart is a static moment in time. The sky, however, keeps moving. Transits, progressions and directions are ways the natal chart can be moved forward in time.
Transits
Transits are the contacts between the moving sky at any moment and a natal chart. As planets move around the zodiac they transit natal planets which are at the same places in the zodiac. For instance, at the time of writing Pluto is at 26 Sagittarius and will transit any natal point at that degree. It will also transit by aspect anything which is at the appropriate degrees of mutable (square or opposition), fire (trine) or air (sextile) signs. Orbs for transiting aspects are tighter than for natal, use 1 or 2 degrees.
Progressions
Progressions are a symbolic measure of time which is based on real astronomical motion.
Secondary Progressions
These use the day for a year analogy. The idea is that if you want to know what will be happening in the tenth year of life you look at planetary positions on the tenth day and so forth. Progressions have been experienced as transits over the first few months of life. The fastest moving point is the progressed Moon. The maximum span of progressions which you will experience in one lifetime is 90 – 100 days, therefore the points which will have travelled farthest are the luminaries and inner planets. There may be periods where Jupiter through Pluto may move particularly quickly and give significant progressed movement but this is unusual. You will also have retrograde motion if points were retrograde over that particular period.
Tertiary Progressions
As for secondary progressions but using a month for a year.
Primary Progressions
Strictly speaking these are directions. See below.
Directions
Directions are a symbolic measure of time which is not based on astronomical motion.
Solar Arc Directions
Solar arc directions move the whole chart forward by the distance the progressed Sun has moved since birth. For instance, if the progressed Sun has moved 30°, which would happen around age 30, then all points would move forward by 30° and the aspect pattern within the chart will be constant. All points are forward moving as the Sun in never retrograde.
The motion of the Sun per year averages out to one degree but, depending on what time of year you are born, it can vary. It’s faster in the winter when the Earth is at perihelion and slower in the summer when it’s at aphelion.
Other Directions
There are other methods. Naibod uses the average solar daily motion. You can progress the chart by any quantity depending on what you wish to examine.
Primary Directions
These are extremely complex to calculate and have fallen out of favour. The availability of computers has revived their use somewhat. Where secondary and tertiary progressions use movement along the ecliptic, primary progressions use movement around the diurnal circle.
Profections
Profections move the points in a chart around by one sign for one year of life. The aspect relationships and house positions are maintained but the signs move round. For instance, if a chart has Aries rising then the profection for the third year will have Gemini rising.
