Synastry is the comparison of the natal charts of two persons in order to assess the potentialities of their relationship. The Synastry chart is a bi-wheel chart superimposing, or overlapping of two natal charts: the inner wheel usually pertains to the female and the outer wheel, to the male. Then, the interaspects between the two charts, and not the natal aspects, are drawn up, i.e. the contacts that the planets and angles in the inner wheel form with the planets and angles in the outer wheel. These contacts are the basis on which the analysis of the couple's potential is developed. There are other methods, such as composite charts, mid-space mid-time charts. The technique for the mid-space chart consists of calculating the mean latitude and longitude of the two places of birth. It produces a fictitious median chart, referred to as mid-space mid-time chart, which represents the couple's relationship, like the composite chart, except that it is calculated with a different method.

Synastry, or the practice of comparing the horoscope of two individuals, is an age-old craft which remains one of the most popular uses of astrology. Most books on synastry focus on the aspects formed between the Sun, the Moon, and the planets in one chart to the other. The synastry charts of any two individuals can be compared; business partners, parent/child, friends, enemies or whatever. Our purpose here, however, will be limited to the comparison of partners in a romantic or potentially romantic relationship. The synastry of love relationships. Here are the astrology factors often considered in a synastry reading:

- Ascendants

- Sun

- Elements

- Moon

- Mars & Venus

- Aspects

- Houses

The Ascendant and the Descendant

The rising sign or ascendant in your horoscope tells much about your personality. This is the factor of the horoscope which speaks to how you will deal with the outside world. And your relationships are a most important part of that outside world. The ascendant degree on cusp of your first house begins the series of twelve houses and determines, to a large extent, the sign that will be on the cusp of each of the eleven remaining houses. The ideal match for you is the personality type denoted by the sign on the cusp of the descendant. The descendant in the horoscope is the sign opposite the ascendant. This sign rules the 7th house. The seventh house is the field of relationships and therefore it is the area of primary focus in a study of synastry. This house, opposite the first (matters of the self), relates to the other people with whom you enter close association. Indeed, the sign on the cusp of the 7th house is the personality type with whom you are most comfortable and best suited. This idea of opposites attracting is a very valid concept in astrology. A person whose chart is the mirror image of yours, has the natural tendency of dovetailing the alliance by filling needs to form a solid unit.

Sun Signs

Astrologers are frequently asked "Which Sun sign is best for me?" The short answer is, there is no short answer. There are too many other variables to consider to charge off looking strictly for someone born while the Sun was in this sign or that. Sun sign compatibility ranks low on my list of factors to focus on when seriously studying synastry. The Sun is about ego and individuality. It is important because it discloses those inborn traits that are not likely to change very much in an individual. No matter what our personality is like, these inborn traits are going to be there and be very apparent. Nonetheless, the Sun sign, which is often the only focus in relationships, is just a bit part in a complete analysis. This said, the oft given advise about Sun signs will be repeated here. The Sun signs fall into four groupings according the elements. Aries, Leo and Sagittarius are the fire signs; Taurus, Virgo and Capricorn are the earth signs; Gemini, Libra and Aquarius are the air signs; and, Cancer, Scorpio and Pisces are the water signs. There is tendency toward affinity within the elements. Each sign gets on somewhat better with other signs in its element. Further, the air and fire groups share more compatibility with one another, as do the earth and water Suns.

The predominate element matches

The elements are indeed important when evaluating a potential relationship. But the Sun sign is only one indicator of which element will be strongest in an individual. Each of the planets is in one or another of the signs, and often the planets out weigh the Sun in importance. By this I mean if the Sun is in a water sign, but most of the other planets are in fire signs, you may actually be more of a fire sign person. The Sun is an important indicator of the element that will be strongest in an individual, but it is not the absolute indicator. You will find significant compatibility with persons having a predominance in the same element as yourself. If your partner is not of the same element as yourself, you must become familiar and tolerant of the differences that should be expected.

The Moon's important role

The Moon has a lot to do with relationships because this luminary denotes the state of emotions and conditioned responses. If the Moon in one chart is square or opposed to the Moon in the partner's chart, chances are there have been some conflicting ideas existing based on backgrounds and previous experiences. A Moon in conjunction with the Sun of the partner is a very good sign in that the Moon person has a wonderful emotional connection with the ego of partner. A favorable Sun/Moon aspect, that is a conjunction, sextile, or trine, can largely smooth out a relationship. Indeed, the relationship between the Sun in the male's chart and the Moon in the female's chart may be even more important than the Sun to Sun relationship.

Mars and Venus

Mars and Venus play major roles in romance and in the mating process. Mars relates to your romantic desires; lust, if you will. It determines how sexually aggressive you are, and the raw passion, or lack of it, in your nature. Thus, Mars takes on the role of pursuit. This is why the symbol of Mars is also the symbol for the male. Venus, on the other hand, relates to the way in which you attract a mate. It represents the softer side of love; romance and emotional response to love. This role of attracting a mate links the sign of Venus with the female. The interaction of the two say a great deal about the chemistry between two people. They are often responsible for the sense of "love at first sight" and what would be called a very strong sexual attraction. Regrettably, love at first sight and a very strong sexual attraction doesn't necessarily make a long and durable relationship. Other factors will be more instrumental in determining this. Nonetheless, a good fit between Mars and Venus adds a wonderful dimension to your relationship. The most auspicious fit here between the partners would be for Mars and Venus to be in the same sign or in the same element. The attachment is much stronger if the planets form a conjunction or trine aspect.

The aspects

The aspects formed between the Sun, the Moon, and the planets in one chart and the Sun, the Moon, and the planets in the partner's (or potential partner's) chart show the detail of how smoothly this relationship will work. Note that virtually every comparison will present some harmonious and some not so harmonious aspects. Don't expect anything else. Very seldom does the "perfect" match occur. By the same token, if nothing but negative aspects appear, the relationship is apt to be a major struggle. Visit synastry aspects for delineations of the major synastry aspects.

Synastry Planets in Houses

Your partner's planets in your houses. Your planets placed in your partner's houses. How does this influence your relationship? Visit synastry planets in houses.