Paul Rincon Science reporter, BBC News August 25, 2006
On Thursday, (August 24,
2006) experts approved a definition
of a planet that demoted Pluto to a lesser category of object. But the
lead scientist on Nasa's robotic mission to Pluto has lambasted the
ruling, calling it "embarrassing". And the chair of the committee set
up to oversee agreement on a definition implied that the vote had
effectively been "hijacked". Read the rest of the story.
Pluto steps down from the
throne, at least for now. Pluto
seems to have been traveling through the underworld of Lilliput during
his recent retrograde travels. He aparently has been captured by the
Lilliputins, to be a bound leader of the little people. But we all know
he will hold on to his dignity even though he's just been crowned
Prince rather than King.
The IAU members gathered at the 2006 General Assembly agreed that a "planet" is defined as a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
This means that the Solar System consists of eight "planets" Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. A new distinct class of objects called "dwarf planets" was also decided. It was agreed that "planets" and "dwarf planets" are two distinct classes of objects. The first members of the "dwarf planet" category are Ceres, Pluto and 2003 UB313 (temporary name). More "dwarf planets" are expected to be announced by the IAU in the coming months and years. Currently a dozen candidate "dwarf planets" are listed on IAU's "dwarf planet" watchlist, which keeps changing as new objects are found and the physics of the existing candidates becomes better known.
The "dwarf planet" Pluto is recognised as an important proto-type of a new class of trans-Neptunian objects. The IAU will set up a process to name these objects.
are changing our understanding of
systems, and it is important that our nomenclature for objects reflect
our current understanding. This applies, in particular, to the
designation 'planets'. The word 'planet' originally described
'wanderers' that were known only as moving lights in the sky. Recent
discoveries lead us to create a new definition, which we can make using
currently available scientific information.
The IAU therefore resolves
that "planets" and other bodies in our Solar
System be defined into three distinct categories in the following way:
(1) A "planet"1 is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
(2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape2 , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
(3) All other objects3 except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".
1. The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
2. An IAU process will be established to assign borderline objects into either dwarf planet and other categories.
3. These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.
Pluto is a "dwarf planet" by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects.
Pluto leaves behind Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, a loving extended family who will surely grieve his passing. He takes with him though, Ceres, Charon, his sidekick, newly discovered UB313, now officially named Eris and many more soon to follow. May they rest in peace.
February 18, 1930 Pluto was discovered by Clyde Tombaugh at the Lowell Observatory in Arizona, when he compared photographic plates taken on January 23 and 29, 1930. After the observatory obtained confirming photographs, the news of the discovery was telegraphed to the Harvard College Observatory on March 13, 1930. The planet was later found on photographs dating back to March 19, 1915 so he was visable but hidden for 15 years. A heated debate and search for a proper name for this unusual body was completed on May 1, 1930, agreeing to name him after the lord of the Underworld, Pluto, as suggested by 11 year old Venetia Burney from Oxford, England. Before this many names had been suggested, including Constance (Lowell). Wisely, they didn't choose a name that implied a lack of change for a body that brings transformation. The only thing constant about Pluto is change.
Pluto is unique in many ways. He rotates in the opposite direction from most of the other planets. His orbital period is exactly 1.5 times longer than Neptune's and for rotating 13 and 20 year periods is closer to the Sun than Neptune, the last time being from February 7, 1979 thru February 11, 1999. The last 13 year peroid was April 30, 1483 until July 23, 1503. The plane of Pluto's equator is at almost right angles to the plane of its orbit, as is Uranus'. The following illustrations show his unique interaction.
The above illustration show Pluto's inclined orbit compared to Jupiter, Saturn, Uranus and Neptune. The illustration below shows Pluto and Neptune are in a 3:2 resonance which prevents their collision or even any close approaches, regardless of their separation in the z-dimension shown above.
Illustrations from Renu Malhotra's Book, "Pluto and Charon.
The minor planet center of the IAU has given Pluto a new designation to identify him as a minor body, announced September 7, 2006. His new ID is 134340. (IAUC 255), only a couple thousand before UB313 Eris even though he was discovered over 70 years earlier. There were 2,225 asteroids being numbered that week and Pluto was given the next in the series with the others after. So it seems the IAU isn't even following their own official prodecure for naming and numbering asteroids. In a separate statement from the Minor Planet Center the same day, Timothy B. Spahr commented that assigning permanent numbers to these objects “does not preclude their having dual designations in possible separate catalogues of such bodies.” So Ceres is number 1 and Pluto is number 134,340.
I see three master numbers hidden here, 33, 44 and 55. 33 is sometimes refered to as the martyrs number. More is expected from master numbers, but more is given in return. It is a number of valour or bravery where one doesn't count the cost of love and service. In the tarot it corresponds to the 7 of wands and in astrology it corresponds to the 3 decan of Leo, in harmony with his current position in Sagittarius.
44 can be called a vibration bringing a truce. It is the 4 of swords in the tarot and the Rider Waite deck show it as a man lying down, not dead, but in quiet repose. The 3 swords of sorrow have been used and put away while on more sword stands ready to use if necessary. Let's hope we can see a truce in the war torn mid east soon. This corresponds to the 3rd decan of Libra were wars are fought and ended with a compromise reached.
I have a feeling Pluto is glad to suffer this slight demotion, at least for the time being, for the good of humanity and our evolutionary growth. No title can negate his power for transformation. Let it be so.
55 is the Ace of Swords in the tarot. It is an air vibration that represents the birth of a special child, perhaps a revolutionary idea. It is the upright sword of Justice demanding fair, high morals and innovative thinking. Since it reduces to 10/1 it shows the need and ability to be reborn or begin anew, but also, the karma of sowing what we reap and reaping what we sow.
To read the telegram from
the IAU visit here
To meet the new body that led to Pluto's reassignment go here.