Geocentric: Planetary positions as seen from the Earth
Each day the positions of the Sun, Moon, Moon's Node, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto change as they move through the zodiacal signs. Sometimes a planet moves retrograde, where it is seen to move backward through the zodiacal signs, and then it moves direct (forward) again through the signs. In the Astrofire chart service it is - with regard to position of the Moon's Node in the chart - the Moon's Ascending (North) Node that is given, this being the point of intersection of the Moon's orbit with the Sun/Earth plane as it rises north of this plane. Moreover, the true zodiacal longitude of the Moon's Node is given in the charts computed by Astrofire, rather than its mean position. The Descending (South) Node is exactly opposite in the zodiac.
The planets also form geocentric aspects with one another - aspects being significant angles between planets, such as 180° (opposition), 120° (trine), 90° (square), etc. In the writings of the German astronomer Johannes Kepler (1571-1630) he puts forward that the aspects are perceived by the Earth soul, which responds in the phenomena of nature such as the weather. In the same way, the human soul responds to the aspects imprinted into it at birth.
Conjunction (0˚) and opposition (180˚) between two planets are the most important aspects since these two aspects signify that an alignment of the two planets takes place. In the case of a geocentric conjunction between Planet A and Planet B, the alignment is Earth-Planet A-Planet B; and in the case of a geocentric opposition the alignment is Planet A-Earth-Planet B. The next most important aspect is the square (90°), which takes place midway between these two alignments.
In making use of the Astrofire chart calculation service (click here), one is requested to specify which aspects one would like to include in one's geocentric chart, and the Aspect Set "Conjunction, Opposition, Square" is the default set. The geocentric birth chart is a map of the soul and relates to the human being's astral body, whereas the geocentric conception (epoch) chart reflects the etheric body - see previous section (click here) for further explanation.
Heliocentric: Planetary positions as seen from the Sun
Each day the positions of Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto change in relation to the Sun. These heliocentric planetary positions are just as important for the incarnating human being as the geocentric planetary positions. Whereas the geocentric planetary positions relate to the level of the human being's astral and etheric bodies, the heliocentric planetary positions have to do with the "I" or self of the human being and how the "I" participates in the building up of the physical body through the spirit seed (for further elucidation regarding this, click here.).
The relationship of the "I" to the Sun is intrinsic to the whole astrological tradition. However, it is only since the birth of heliocentric astrology in the twentieth century that some - actually only very few - astrologers have begun to cast the heliocentric birth horoscope. This is the horoscope of the "I" or self. The Astrofire chart calculation service also enables the heliocentric horoscope of conception (epoch) to be computed - this is the horoscope of the spirit seed underlying the formation of the physical body.
The planets in their movements around the Sun also form heliocentric aspects with one another - significant angles between the planets as seen from the Sun, such as 180° (opposition), 120° (trine), 90° (square), etc. The human "I" responds to the heliocentric aspects imprinted into it at birth. In the case of a heliocentric conjunction between Planet A and Planet B, the alignment is Sun-Planet A-Planet B; and in the case of a heliocentric opposition the alignment is Planet A-Sun-Planet B. The next most important aspect is the square (90°), which takes place midway between these two alignments.
In making use of the Astrofire chart calculation service (click here), one is requested to specify which aspects one would like to include in one's heliocentric chart. The Aspect Set "Conjunction, Opposition, Square" is the default set. The heliocentric birth chart relates to the human being's "I", whereas the heliocentric conception (epoch) chart reflects the spirit seed - see previous section (click here) for further explanation of this.
Tychonic (Hermetic): Planetary positions are heliocentric, as seen from the Sun; at the same time, however, the Tychonic (hermetic) horoscope treats the Earth as the center, since this is the perspective of the incarnated human being
The Tychonic system - named after the Danish astronomer Tycho Brahe (1546-1601) who introduced it - is a helio-geocentric system. It is described at length in Robert Powell's Hermetic Astrology, volume I. In the Tychonic horoscope, which is also called the hermetic chart, the planetary positions are heliocentric, but the entire framework of the horoscope is geocentric, since the horoscope includes the positions of the Sun, the Moon, the Ascendant, and also the other House Cusps, which are all geocentric.
One important feature is that additional aspects arise in the Tychonic (hermetic) chart which are not found either in the geocentric or in the heliocentric horoscopes. For example, the hermetic aspects involving the Moon. For instance, there is an exact hermetic conjunction of the Moon and Venus in the hermetic horoscope of Marilyn Monroe, whereas Venus is otherwise unaspected in her birth horoscope, and there is an exact hermetic conjunction of the Moon and Mars in the hermetic horoscope of Andy Warhol, in whose geocentric horoscope there is no relationship between the Moon and Mars.
Hermetic means "hidden" and the aspects of conjunction and opposition of the Moon to these heliocentric positions of the planets are indeed hidden from us. Nevertheless they are intrinsic to the helio-geocentric astronomical system of Tycho Brahe used in modern hermetic astrology, which is thus called the hermetic system. Years of research show that the Tychonic (hermetic) chart is highly significant for an understanding of the human "I" or self. In the Tychonic (hermetic) system the heliocentric movements of the planets are retained, but instead of the Sun, the Earth is regarded as central. The aspects involving the Earth become modified to aspects involving the Sun, according to the change of perspective from the Sun to the Earth. If the hermetic viewpoint is adopted, as in the Tychonic system, this viewpoint is essentially Christocentric, recognizing that - through Christ's sacrifice - the Earth has become the center in a moral and spiritual sense. And it is striking that at the transfiguration of Christ on Mt. Tabor there was a hermetic opposition between the Moon and Venus, and at the descent of Christ into the underworld after his crucifixion there was a hermetic conjunction of these two planets. Click here to read more about the Star of the Magi and the life of Christ in relation to the stars.