by
a21cent
@ Wednesday, 09. Aug, 2006 - 09:24:37 pm
For the past few years there's been increasing debate about whether Pluto should remain classified as a planet, or be downgraded to a Kuiper belt object.
As a certain mobile phone company advert keeps reminding us lately, the world's not so rigid these days (shades of the Saturn-Neptune opposition) and astronomers have been adjusting their views of the solar system - and the universe - as more and more new objects have been discovered that defy traditional classification. For instance, just the other day, astronomers announced the discovered of some 'planemos', which blur the boundaries between stars and a planets (see BBC link below).
The solar system is no longer relatively simply populated by a star, some planets, some moons, some asteroids, and some visiting comets, with clear-cut distinctions between them all. It's now known to contain comets that behave like asteroids and asteroids that behave like comets. It has cubewanos, plutinos, centaurs, trojans, and more. It's as if our view has had to be shattered and broken apart, so that we can accommodate the new.
Some astronomers argue that Pluto is a Edgeworth-Kuiper Belt Object, or EKO, and not a planet. The Edgeworth-Kuiper Belt is an area of the solar system extending from Neptune outwards for 20AU (Astronomical Units - 1AU is the mean distance from the Sun to the Earth) wherein icy rocks orbit, like a second asteroid belt.
An astrological perspective sees meaning in the very discussion. Back when Saturn was the outermost known planet in the solar system, it made sense that Saturn represented normality, convention, boundaries, limitations, endings, and finality. The planets beyond Saturn have been seen as symbolising different types of change that lie beyond the Saturnian norms, bounds, and conventions.
Pluto has been classified as a planet since 1930, but there are now objects being found that are challenging the definition of 'planet'. Some argue that if Pluto is a planet, then so are many other solar system objects. Others argue that if those other objects aren't planets, then neither is Pluto. The human conception of the solar system is definitely in transition.
In astrology both Saturn and Pluto 'rule' endings. The difference between them is that Saturn is an ending pure and simple, whereas Pluto is an ending that precedes a new beginning. It's interesting that the definition of 'planet' may end because of this situation with Pluto, and may begin again in a new form because of it. Some of the arguments have been surrounded by political (with a small 'p') manoeuvres and power struggles, suitably Plutonic in nature. Once the situation is decided, as with all things Plutonic, things are sure never to be the same again.
About the Edgeworth-Kuiper Belt (includes diagram)
http://www.harmsy.freeuk.com/kuiper.html
Planemos discovered
http://news.bbc.co.uk/2/hi/science/nature/5241774.stm
About the worlds beyond Neptune
http://www.space.com/scienceastronomy/051219_mystery_monday.html