Software to calculate geocentric and heliocentric planetary positions,Sale today: For a short time only you can obtain a 33% discount on all programs on this site (perpetual user licenses only) if ordering via Comecero. To get this discount, enter one-third-off as the discount code at the Comecero shopping cart (and click on 'Apply').
aspects, aspect patterns, world transits, personal transits and synastry
May 13, 2021, 12:00 GMT
Julian date: 2,459,348.00
Ecliptic longitudes Planet Geocentric Heliocentric Sun 52°57' 22Tau57 Mercury 74°20' 14Gem20 168°42' 18Vir42 Venus 65°26' 5Gem26 83°6' 23Gem6 Earth 232°57' 22Sco57 Mars 102°10' 12Can10 129°52' 9Leo52 Jupiter 329°57' 29Aqu57 318°31' 18Aqu31 Saturn 313°26' 13Aqu26 307°42' 7Aqu42 Uranus 41°24' 11Tau24 40°50' 10Tau50 Neptune 352°42' 22Pis42 351°2' 21Pis2 Pluto 296°45' 26Cap45 295°14' 25Cap14 Moon 71°26' 11Gem26
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The programs on this website are based on exact astronomical algorithms. They are mostly described here as if they were merely astrological, but they are also useful in the areas of astro‑trading and astronomy.
There are several different types of astrology program. One difference is whether the program concerns geocentric astrology, heliocentric astrology, or both. In geocentric astrology the zodiac is viewed from the perspective of the Earth, whereas in heliocentric astrology it's from the perspective of the Sun. Most astrological software is geocentric, but astro-tradng programs often use a heliocentric zodiac. Some of our programs are purely geocentric, one is purely heliocentric, and the others support both zodiacs.
The programs below run with all versions of Windows, and on Macs with an emulator. Trial versions are freely downloadable can be made fully-functional by means of an activation key after purchase of a user license. Updates to new versions are free. For more details and to purchase a license either click on an image below or visit our Software Shop.
What's a planetary transit?
Planetary aspects occur when two planets possess a particular angular relationship with each other (e.g. conjunction, opposition, trine, square, etc.) with respect to a central point. This point is either the Earth (in geocentric astrology) or the Sun (in heliocentric astrology). A planetary transit is the period during which two planets remain continuously in a particular aspect with each other.
The programs described here either display planetary aspects and transits or calculate the exact dates and times at which transits occur (begin and end) between selected planets. Click on any of the program titles or screenshots for more information about a particular program (and the user manual). Or to get short descriptions of these programs visit our software shop.
Astrology without houses
The reason that none of these four programs involve an ascendant, or astrological houses, is that the ascendant (and thus any house system) depends on a geographical position (usually a birthplace). But aspects between planets, and thus planetary transits, depend only on the motion of the planets along the ecliptic as viewed from the Earth (or the Sun). Thus a planetary transit does not require, or imply, an ascendant (and thus no house system). Aspects and transits have their own astrological meaning. (Yes, astrology without houses is possible.) Signs (derived from the equal division of the ecliptic) are as usual, for example, Neptune is in Pisces from April 4, 2011, through March 30, 2025; and see this Su‑Me‑Sa‑Pl 4‑stellium in Capricorn on January 12, 2020). For a heliocentric example see this double kite.
There are 7 house systems commonly used by astrologers, and over 20 are possible. They give different results when interpreting a horoscope (and the Koch and Placidus systems don't even work for all latitudes). Which gives the "correct" interpretation? Or should we just conclude that the "meanings" given to houses are (arbitrary?) choices made by astrologers long ago, uncritically passed from generation to generation, and that only aspects (especially aspect patterns) and transits are important (and still to be properly interpreted)?
The developer of these computational astronomy/astrology programs (Peter Meyer) is currently available for custom software development at an affordable rate. If interested please leave a message here.