The Astrological Definition of a Planet
Astronomy will always be in a quandary as to what constitutes the term "planet" because they are dealing soley with physical or material considerations. Astrology, on the other hand, also takes into account the spiritual or esoteric component, which is just as important, if not more so.
Basically, a planet, in astrology, is a sphere or world that is bestowed with great spiritual power or significance. More specifically, it is a visible representative of one of the twelve zodiac signs with all of its attributes and functions. Zodiac signs are divine spiritual energies which manifest through matter -in this case, the planets. There are twelve signs, which in turn necessitate twelve planets.
endowed with astrological power, and size or distance has little to do with it. Major planethood is an exclusive club limited to twelve members, and while any of the members can be replaced, the number remains fixed at twelve. Only if the number of zodiac signs increases will there be more members. In greek mythology, there were twelve major Olympian gods. When, for example, Hestia left and there were eleven, Dyonysus took her place to bring the number back to twelve. Similarily, In the bible, there were twelve apostles. When Judas left he was replaced by Matthias.
What distinguished the major from the minor gods was not their size, but their POWER, and this should be the main criterion for planets. I doubt, however that an astronomer can measure a planet's "spiritual" power. Astrologers are much better suited to this task.
A planet's spiritual power separates it from the rest. This power comes from its logos or god who resides at the planet's inner center. A logos generally occupies planetary office for some 2000 years or so (an astrological "age") before moving on or being replaced. Like in earthly politics, however, there are possible impeachments or multiple or extended terms. Apparently, Earth and some of the other planets have yet to enthrone or instate a true or appropriate logos. A planet's rings or the lack thereof often signifies its kingship or standing.
The major "planets" of our solar system, from a geocentric and astrological perspective, are: Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn(the classical or traditional seven), Uranus and Neptune (discovered telescopically in 1781 and 1846 respectively and adopted by modern astrology), and the fixed Stars. Each of these bodies rules over one sign with the exception of Mercury and Venus which still rule over two signs. The acceptance of two more planets will even the rulership scheme.
Recently, Pluto, ruler of Scorpio and king of the Underworld was demoted from major to minor planet status. Ceres, Charon, and newly discovered "Xena" which were also to be promoted to planethood, also did not pass the major planet test according to the latest definition. Instead, all three(Charon went back to being Pluto's Moon) have come to be categorized as "dwarf planets". In the eyes of many, and especially the astrological community, Pluto's downgrade was an unfortunate mistake. This ruling, however, succeeded in keeping countless other and possibly unworthy bodies from becoming major planets.
Why is Earth not regarded as a "planet" by astrologers? This seems to stem from the notion that the ancients regarded Earth as the fixed center of our universe, around which all other bodies apparently revolve. This view was never seriously challenged untill the Renaissance was well under way, slowly eroding the power of the Church and its doctrinal beliefs.
The fact is that Earth is indeed a planet, and that while its centricity is the basic and correct premise for doing astrology, this should not negate its status as a planet. Because we live on Earth, it's astrological influence or power comes to us in a very special or ingenious way -via the ascendant(rising sign) or eastern horizon. Providence has seen to it that it affects us just like any other planet, despite the fact that it is right under our feet!
Astrologers have failed miserably to make the connection between planet Earth and the so-called Ascendant or Rising sign in astrology , or at least bring it to the public's attention. This is either gross incompetence or perpetrated negligence on the part of astrologers or whoever they answer to. It is perhaps the single most important reason why astrology has not been taken seriously by the scientific community. Unless this situation changes astrology will continue to be regarded as a baseless superstition by the world's major bodies of knowledge.
There is a twelfth body which astrology has yet to accept or incorporate into its structure before it can be considered a complete discipline. This body has even today eluded most astrologers(including this author), and so cannot expand on it with any certainty. It has gone by many names, most notably, Vulcan, Planet X, Nemesis, Nibiru, the Twelfth Planet, the brown dwarf, the sun's binary, and so on. Perhaps it is already well known and classified by the select few, I cannot say, but it is out there and awaits to be revealed. NASA has launched a probe (New Horizons) to check out Pluto, but it will not arrive until 2015, and since we do not yet have the technology to view this possible planet from earth, we'll have to wait another 3 years before we get any concrete answers.
Astronomers have much to learn(and unlearn) about the true nature of our cosmos, and it is not in their best interests to denounce or ignore all sources of knowledge that may help or contribute, whether they be scientific or otherwise.