Predictive Techniques: Solar Arc vs Secondary Progression

Solar Arc vs Secondary Progression: Which Systems to Use?

Secondary progression (i.e. “a day for a year” method of directing a natal chart) has been around for a long time, but it was by no means the only method of progressing a horoscope. Throughout the history of astrology, astrologers have invented different methods of projecting a natal chart into the future.

Right now, Solar Arc and Secondary Progression are the most popular methods used by professional astrologers.  Noel Tyl popularized the Solar Arc method (although he still uses Secondary Progressed Moon). There are many fine astrologers using Secondary Progression as their tool of choice, so both methods are here to stay.

Difference between Secondary Progressed and Solar Arc Planets

One of the key differences between the two methods is that in Solar Arc you get to advance the slower moving planets (Saturn through Pluto) that hardly move in the Secondary Progression method, so this tends to add more interpretive possibilities when forecasting.

Noel Tyl, who has written extensively about both progression methods, stated that in our modern era, important life changes (e.g. divorce, job change, relocation, etc) occur much more frequently than in previous times – thus we need a method that more accurately reflects the rapid pace of modern life.

In Secondary Progression, outer planets are pretty much unusable due to how slowly they move.  In Solar Arc, you’ll see natal outer planets located in cadent (3rd, 6th, 9th or 12th) houses crossing an angle within the first 10-30 years of life, frequently representing major restructuring of family unit, home environment, or the profession.

How to Calculate Solar Arc Planets’ Movement

Solar Arc planets “move” at the speed of Secondary Progressed Sun, which is approximately one degree per year.  If you obtain the current location of SP (secondary progressed) Sun, and calculate the arc (angular distance) between the SP Sun and the natal Sun, you have the “Solar Arc” you need to progress your natal chart to its current Solar Arc position (your astrology software will make this calculation for you automatically.)

Even a fast-moving planet like Venus will have a longer time frame (say 6 months applying, and 3 months separating) to be in orb using a Solar Arc method: this means Solar Arc of Venus aspecting the natal Sun (written Venus=Sun) would last for about 9 months, strongly suggesting the success of a relationship or an artistic endeavor.

In transit, Venus moves so fast that it can’t have much of an impact except for a couple days of pleasantness. Similar things can be said of Jupiter, whose transit is fleeting but under the Solar Arc, suggests a 9 months period in which reward or opportunity is likely to be presented.

Testing Solar Arc in Your Own Horoscope

Solar Arc is relatively easy to test in your own horoscope: add 1 degree per year to the natal planets to see how they move and form an aspect with the natal planet. The orb needs to be exact (less than one degree) in order for the Arc to be in effect, and we count hard aspects (conjunction, square and opposition) only.

If natal ASC (Ascendant) is at 12 Leo, and natal Saturn is at 22 Leo, this means Solar Arc ASC will conjoin natal Saturn at age 10 (we write ASC=Sat to denote this period), then we ask if there had been a status change within the family around that age: some Saturnian event such as death in the family, sickness, move, or change in father’s position, etc.

Conclusion: Secondary Progression vs Solar Arc?

Solar Arc is a modern derivative of Secondary Progression that allows the astrologers to utilize Saturn and outer planets more fully in their predictive work.  Many modern astrologers including myself use Solar Arc (which gives central importance to the Secondary Progressed Sun’s movement) in combination with Secondary Progressed Moon (which is a very important timer of life progress.)

To study further, you can read the article on Solar Arc Interpretation.

A Must Read Reference: Solar Arcs by Noel Tyl

Noel Tyl has written extensively about his method of prediction in Solar Arcs: Astrology’s most successful predictive system. The book is actually a summary of his predictive method incorporating transits, Solar Arcs, Secondary Progressed Moon, as well as Tertiary Progressed Moon.

About Hiroki Niizato

Hiroki Niizato is a professional consulting astrologer in Florida, serving clients in US and abroad. He has been practicing astrology professionally since 2001. Hiroki is a highest honor graduate of the demanding Master’s Degree Certification Course in Astrology by Noel Tyl.

You can contact Hiroki via email at: or schedule a consultation.


  1. Hi Hiroki, thanks for sharing your extensive knowledge. Do you use relocated natal charts for your progressed / solar arc charts? Thanks.

  2. Hello Hiroki!

    I have SA Venus conjucting my Natal Sun; SA South Node conjucting my Natal Venus; and SA North Node opposing my Natal Venus, all at 0 degrees 20’. Reading your articles, am I correct to interpret that a significant love encounter will manifest in the next 6 months? I also have SA MC conjucting Jupiter in 1 degree, which means opportunities to develop my career and vocational ambitious will develop within one year? Would really appreciate if you could help me with this! Thank you

    • Hi Natalia, yes, so SA Venus=Sun indicates a strong activation of your social life, and love encounter can certainly be a possibility. MC=Jupiter is also a strong activation of your career/success potential, so these look very promising.

  3. Hi Hiroki! First of all thanks a lot for information since there is very limited information about solar arcs.
    In my solar arc chart, uranus, neptune, pluto and saturn are between 29-30 degrees recently. They are all going to be in the next sign by the end of this year. In my natal chart, mercury and MC at 29’21 and 29’23 degrees (both in virgo). In june, solar arc uranus going to be squaring to both in 2 weeks. At the same time (in couple of months) solar arc north node conjunction pluto (10. house) and solar arc mars conjunction north node (9. house) are taking place. When I looked at the transits for the same date, I saw some transit planets aspecting to the same point (MC) Should I be worried about it or see this as an opportunity for my career since I’ve been having trouble with this area of my life lately. Thank in advance.

    • Hi there, from what you shared, the especially important ones are Solar Arc Mercury and MC to the Aries Point (29 mutable about to reach 0 Cardinal). This is indeed a signal that your career is about to experience a visible shift, most likely in a good way. For a full analysis please consider scheduling a private consultation.

      • Hi again Hiroki, thanks for your quick response. I think I caused some confusion when I shared my natal chart information, the 29 degrees in Virgo are in my natal chart. Right now, I have several 29 degrees in my SA chart. My SA Uranus is in the first house, 29,21 degrees of Sagittarius making a square with natal Mercury and natal MC in 29,23 Virgo. Around the same time SA Mars (7,18 degrees Virgo) will be conjunct my NN (7,26 degrees Virgo) in 9th house, and recently I also had SA NN conjunct Pluto at 18 degrees Libra in my 10th house.
        This all seems important, but I don’t know what to make of it.

        • Understood, so what you have is SA Uranus = Mercury & MC all at the Aries Point. My comment earlier still applies in this case – a shift in your career situation is likely.

          • I read your article on aries point and It is clear now. Thanks a lot for your explanation!

  4. donna farmer says

    Question:. If a person’s solar arc Jupiter is exactly conjunct their natal Mars in the 5th house, and Mars is Jupiter’s ruler in the natal chart, does this possibly denote some particularly lucky time for them? (Lottery, etc.)

    • Hi Donna, you can consider Solar Arc Jupiter=Mars as a strong activation for the Mars energy. In the 5th house that can fire up the desire to play, have fun, and otherwise take action with a lot of optimism (so at least you’ll feel good buying that lottery ticket). It’s a great time for physical exertion as well.

  5. Hi Hiroki
    Thanks so much for this insightful blog!
    Have you ever seen a person’s solararc chart is the exactly the same as their draconic chart. I was shocked to realize this today. Mine will be EXACTLY the same for 2019/2020!
    Thanks so much, Pinar

  6. Hi Hiroki,

    I have a question about my solar arc north node (28-57 Pis). It is exactly opposite my natal Pluto (28-58 VIR) right now. Do I need to be concerned about harm coming my way. Should I be extra careful right about now. And if so, for how long.

    Thanks for your thoughts on this !


    • Hi Rosie, Nodal axis events often suggest a meeting, and/or an involvement with groups – in this case (Node=Pluto) there could be an important significance for such a meeting.

  7. Hi Hiroki,
    A friend and I were discussing solar arcs today and a question came up and we thought of you ! Can you let us know how many solar arcs – exact to a natal planet are required to trigger an event. If someone has 4 solar arcs hitting a natal planet exact to the degree at the same time that 3 progressed planets are hitting a natal planet to the exact degree as well as 2 transits exact over a natal planet, would you consider this a lot of activity that would most likely trigger an event, or is this just common activity that happens. Ironically, all of these happen in H5 and House Ruler of the 7th …. we see a theme happening here !
    Thanks for your opinion. She says yes, I seems to think if you look hard enough, you are sure to find something when looking at transits, progressions and solar arcs. Thanks for your thoughts on this.
    By the way, we love your site !
    Happy New Year to you and Everyone !!!

    • Hi Maggie,

      There is some truth in what you say: “I seem to think if you look hard enough, you are sure to find something when looking at transits, progressions and solar arcs.”

      Astrologers trained to use solar arcs by Noel Tyl (he’s the one responsible for popularizing the method) typically do not include secondary progression, with the exception of secondary progressed Moon (which is important). This way you keep the number of measurements manageable (solar arcs and transits plus SP Moon).

      With that said, 4 solar arc measurements occurring at the same year would definitely suggest activity that year (know that a degree equals nearly an entire year in solar arc, so you might need to look at the minutes to see how close the occurrences are).

      • Hi Hiroki,
        Yes, I agree with you.
        Looking at solar arcs only, there are actually 5 in total (not 4). Two are at exact degree and minutes, two are at exact degree and 18 minutes and 20 minutes and the 5th is at 43 minutes. So I think at least four of the five are pretty close to exact as can be.
        Will be interesting to see what happens – especially since all these happen to occur in 5th and 7th house rulers.
        Thanks again and enjoy the rest of your evening .

  8. Bonnie Sayers says

    thanks for the info. I will have to figure out when to get this done over the next few weeks. I had meant my second saturn return, not solar.

  9. Bonnie Sayers says

    I just noticed I have some Solar Arc Progressions coming up and wondered how significant they are.

    1. my Solar Arc Progressed Pluto is at 28’24 Libra. On 1-1-18 my Solar Arc Progressed Pluto will be at 0’05 Scorpio. My third House.

    2. Mid 2019 my PR Moon hits my natal pluto 3’59 and virgo ascendant of 4’17.

    3. on October 26, 2018 my Solar Arc Progressed Jupiter will be at 0’01 Pisces. My natal Chiron is 0, natal mars is 6 and my descendant is 4 degrees. Plus my MC is 29 Taurus.

    At the same time I will have Solar Arc PR Uranus opposite my natal Sun – forming at 0.1

    On another post last June I posted about My Solar Arc Progressed Moon is at 3’25’25 Virgo in 12H. You commented that I would start to feel it this October.

    Do your readings cover all this? When is a good time to prepare for these that occur from 2017-2019? My second solar return will be at 17 CAP in 5H and my Jupiter return will be about the same time – Dec of 2019.

    My PR moon moves into Leo this summer. I had a nodal return in January of this year and will hit again at 23 Virgo in first house. Not sure this means anything but my Solar Arc progressed vertex is at 24 Pisces, which just passed my natal South Node and Venus of 23 Pisces 7H.

    • Hi Bonnie, the best place to discuss these upcoming measurements will be in a personal consultation, as I’ll be looking at all major transits, arcs and progressions for the next several years. I don’t use jargon in my consultation (please see the consultation page for details) but you can ask me technical questions toward the end if you feel the need.

  10. Hi Hiroki, Jupiter in my SA is moving from my natal 6th house into my natal 7th house, it’s been in my 6th house a very long time, it is a little over 1 degree away from my natal descendant, will this improve my relationships and any partnerships?

    • Hi Sandi, that’s noted as Jupiter=ASC, which will be exact in a little over 1 year. This has very nice potentials for any area of life, including relationships. You’ll want to make sure to take advantage of this opportunity through seeking expansive, uplifting experiences and connections.

  11. Hi Hiroki
    just realised I have SA Neptune 1 degree away from Natal Asc.. is this good?Thanks: Learning so much from your ACES website! ~=}

  12. Hiroki – I will try to follow your advice to be patient as I wade through the Neptunian Fog. In the meantime, I think I'll try to make the best of it by finding an appropriate outlet for my artistic talents. Thanks for sharing your wisdom — I do appreciate it.

  13. Hiroki Niizato says


    Major measurements like those you listed here suggest a time of profound shift in self perception – at least the opportunity for this is abundantly there, in the form of your current challenges.

    ASC=Neptune is tricky, and is bound to be accompanied by some confusion for a time. Be patient here.

    Best regards,

  14. I just took another look, and Solar Arc Uranus just entered my 2nd house several months ago. This 2nd house theme seems to be a recurring one. And in my natal chart, I have a stellium there, which includes my North Node.

  15. Hi Hiroki – Solar Arc Pluto is nearing a conjunction (within 1 degree) to my natal Sun (in the 2nd), Solar Arc Mars just squared (and is still within 1 degree) my natal Venus (also in the 2nd), and Solar Arc Ascendant is almost exactly conjunct my Natal Neptune(where else, but in the 2nd).

    Lately, our financial situation has been challenging, and this has caused me to seriously rethink my “value” to the world, which has been very confusing. If you have any insights as to how to interpret these Solar Arcs, I’d be very appreciative. Thanks very much.

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