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The Sun-Mars Synodic Cycle

Mars is currently retrograde, so close to the earth and at its brightest in the sky. Since it’s opposite the Sun now, look for it in the eastern sky after sunset. And now you can see Jupiter and Venus in the western sky. These are beautiful nights for star gazing if you are lucky enough to have a view and clear skies.

The synodic cycle of Mars and the Sun is the period between two consecutive conjunctions of these planets. The synodic cycle with Mars is not totally consistent, but somewhere around 25-26 months. The actual length will be between 762 – 819 days, with an average length of 779 days. (1)

We can consider the cycle to begin at the superior conjunction when Mars is in direct motion and conjunct the Sun. The cycle reaches the halfway point at the opposition between the Sun and retrograde Mars. The current cycle began on February 4, 2011, with the Sun and Mars at 15º Aquarius. We’re just past the opposition — it was on March 3, 2012, with the Sun at 14º Pisces and Mars retrograde at 14º Virgo.

We are all born with Mars (and each of the other planets) in a synodic relationship to the Sun. We most commonly think of the Sun-Moon cycle — the arc between the two luminaries at birth. That arc, called the phase angle, repeats every 29 days. (Astrologers have commonly used this, sometimes for determining times of fertility in a woman’s horoscope.)

The late Robert P. Blaschke demonstrated a sophisticated theory and practical use of synodic cycles in his 2006 book, Holographic Transits, which I reviewed for TMA.

Robert first explains the mechanics of the synodic cycles of all 10 planets with the Sun. He shows how to work with the phase angle return charts, that is, the time within the cycle when the birth angle repeats itself. These vary in frequency: Venus is every 584 days; Mercury, every 116 days; and erratic Mars, who’s average is 779 days.

Along with his impeccable explanation of the mechanics of the synodic cycles, Robert proposes a theory that considers the fate vs. free will question. He writes about astrology as depicting the space-time continuum. He describes the transits to the birth chart as connected to one’s fate, which is associated with time. He then describes free will as related to space — the recurrence of the synodic cycles, i.e., the phase angle return, of a birth chart is related to free will.

The practical application of this theory is that the phase angle return is when the individual can most directly and efficaciously use free will to change patterns related to the particular planet during one’s life.

Regarding Mars now, anyone born with Mars retrograde just past the opposition to the Sun with be having the phase angle return sometime in the next few days. (I’m paying attention to this because I have retrograde Mars inconjunct the Sun — before the opposition — and had the phase angle return a few weeks ago.) Remember, with Mars the phase angle return will only be every 25 months or so. If, for instance, you were born with Mars in a closing square to the Sun, your phase angle return will be sometime around June 7, when Mars in the sky at 18º Virgo will square the Sun at 18º Gemini.)

Another idea from Robert: people born in the same prenatal synodic cycle are part of a “soul group” who have incarnated together. (This notion does explain why you can have an especially close or familiar feeling about people born close to you, again specifically depending on the planet you are talking about.)

Since Mars is the subject here, look (in the ephemeris) for the conjunction of Mars with the Sun that occurred before you were born. Cast a chart for that conjunction at your place of birth. In the case of Mars, Robert felt that “one’s individual hologram of passion emanates from an immense ‘desire matrix,’ of which one is a part.” (2) He also said that those born in our same Sun-Mars synodic cycle have “similar karmic inclinations and tendencies, as well as similar leadership abilities.”

The degree symbol (Sabian or any other symbol system) for the Ascendant shows one’s personal place within that group. The degree of the conjunction is also significant as well, of course.

I spent time yesterday looking at family member’s prenatal Sun-Mars conjunction charts cast for the birthplace and it was riveting. The aspects to the conjunction are important as well. (I have the prenatal Sun-Mars conjunction in an exact square to Uranus, which feels like it says a lot about me, and, as Robert writes, it will also describe all the souls born within that 25-month cycle. The Ascendant degree is what makes it specific, as well as the way the prenatal conjunction chart interacts with the natal.)

Have fun with this if you’re inclined to try it out with your own chart. I’d love your feedback.

We miss you, Robert!


(1) Astrology, A Language of Life, Vol. V: Holographic Transits, by Robert P. Blaschke, Earthwalk School of Astrology, 2006.

(2) Astrology, A Language of Life, Vol. V: Holographic Transits, pg. 128.


  1. Hi, Mary.

    I’m a little confused and have a question for you about this part of the article: “Since Mars is the subject here, look (in the ephemeris) for the conjunction of Mars with the Sun that occurred before you were born.”

    Do you mean to find the degree of Mars which is the same as the degree of the natal Sun, even if there wasn’t an actual Mars/Sun conjunction on that day? For example, if the natal Sun is at 23Cancer, look for the day that Mars was at 23Cancer prior to the birth no matter where the Sun really was on that day?

    Or, are we to look for the day that there was a real conjunction in the sky with both Mars and Sun at 23Cancer?


    • Hi cjwright,

      Thanks for commenting…yes, it’s the day when the Sun and Mars were conjunct before you were born…will usually be different from the natal places (unless you were born close to a Sun Mars conjunction)..

      Let me know if that helps..


      • Yes, that’s clear now. I’ve got my dunce hat on.

        This is an interesting article, Mary, and (obviously) new to me. Thanks so much!

  2. Thanks Mary, looking forward to seeing Mars rise with the Moon and Regulus the next couple nights.
    Speaking of Regulus, I really hope that Robert finally gets the Regulus award he so deserves for his cutting edge brilliance. Studying the pre-natal conjunctions (of all the visible planets) has changed me and my practice forever
    Miss you Robert!

    • Hi Gary,

      Yes, speaking of Regulus…I spoke with Carol at length this morning…we are (with my sister Kate) rooming together at UAC and are looking forward to seeing you..

      I told Carol how Robert was nominated..she and I are both absorbing Robert’s Holograpic Transits in a new way..(I think Neptune is Pisces is helping everything 😉

    • Hi Gary,

      That is a great review…you synopsis the book beautifully..

      everyone interested in Robert’s last book should read it

  3. I really, really enjoyed your article. Thank you so much. Is it possible for the conjunction to be several months back? Looking in the ephemeris I believe that the conjunction happened at 12 Capricorn a few months before my birth. At birth the Sun/Mars was Mars 4Taurus/Sun 4 Gemini.
    By the way this rang a little bell in my heart. I have always lacked ambition preferring to act only when essential to survival,etc. With Sun/Mars exactly 30degrees and in the early part of the cycle I am thinking that although I can get the work done I always like to retreat back into my subjective state.
    Now onto family . I am interested to see if others in the family have the same pattern. I had never really thought of this.

    • Hi Clymela,

      yes, the conjunction can be as much as 24 months before your birth..

      Let me know if you need help figuring it out precisely..

  4. Is there an easy way to find the sun/mars conjunction before a birthdate?

  5. it seems like for the whole year before I was born, mars just scooted ahead of the sun.

  6. ok, found it. So what time of day do you cast this chart for?

    • Hi mimi,

      you need to set the chart for the exact time of the conjunction…you’ll need to find that with software (unless you’re used to calculating manually)…

      let me know if I can be of further help..I may have time to figure it out for you, please send me an email if you need my help…

  7. Mary- You outdid yourself here in explaining a slightly obscure concept slowly and simply taking one stage at a time and making it relevant to the time now. It is not only Robert’s brilliance that shines but your own…

    • Dear Kate,

      I attribute all of my wits to having you as a roommate for all those crucial formative years…


  8. Thank you Mary for this clear, accessible article on Mars-opposite-Sun. I call this the Transcendence Phase of Mars, one of his 13 Phases. I call it this because of the sky factors of Mars at his opposition: closest to Earth, fastest retrograde and furthest from the Sun (with us in between them).

    Thanks to Gary Caton, with whom I recorded an extensive review of this Transcendence Phase (opposition) which can be found at his, I’ve finally released a very long essay I wrote and have been refining for several years on this topic. I realize within the energy now of Transcendence that I’ve been protecting it like a child and it’s time to release it, which I’ve done. yay!

    Since there are so few astrologers who know about the synodic cycles of planets enough to work with them in their practice, I though I’d mention it here. Here’s the link: There’s a 6-page free excerpt of the full 50-pg piece along with a description of the contents of the essay.

    Blessings for Us All!

  9. My prenatal Sun/Mars conjunction is part of a huge Leo stellium, including the moon. This is perfect for the longevity of my public school friendships — a core group of people who have stayed connected across the country, and across countries. I met all of them performing (in orchestra, in choir, in musicals), and most of us are still excessively expressive, playful people. Bonds are still tight among my high school class as a group. A Washington lawyer actually said, at our 20 year reunion, how he wishes we could all go back to school together for a month. This astro-info explains a lot. THANK YOU SO MUCH, MARY!

    • that is a great report, Kathy..thank you for letting us know..


  10. well, this is disturbing…. :^)

    my prenatal sun/mars conjunction is at 6 scorpio, exactly on my natal neptune! in the interests of discretion, i’m not going to explain how well that applies, but trust me, IT DOES! this PNC also occured on or about the date i was conceived, and squares the natal sun.

    thanks, mary, for another piece of the puzzle!

    • Hi Alex,

      I loved what you wrote…I have my own personal astrological reasons for understanding that some things are better left unsaid 😉


  11. Hi
    I looked for a conjunction between sun and mars at the same degree as my natal sun. This took me to December 15 1961. What does this mean? Does it mean that the next time those two conjunct at the exact degree in the sign of Sagittarius, that I will be able to change my life as I wish??? By the way, neither my natal sun or mars are in Saggittarius.
    If I cast my chart, how do I do the ascendant? Do I put the time of day I was born in as usual?

    Yours curiously,

    • Hello Flavia,

      I just saw this comment, sorry for the cast the chart for the exact time of the Sun Mars conjunction before birth. You set it for the place of birth and the Ascendant will show itself.

      (If this is confusing, send me your birth data ( and I’ll figure it out for you..;-)



  12. This is very interesting. My pre-natal Sun/Mars conjunction occurs at 22 degrees Scorpio in my 11th house – I have the Sun at 22 degrees Aries – so they are in quincunx aspect. My son is a Scorpio and I have had many friends (and 1 wonderful loving relationship) with Scorpios. My natal Mars is in Pisces so all that dreamy, romantic stuff goes on in a hot headed Aries – knights in armour and warriors in battle – certainly describes much of my life!

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