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The Pluto Controversy August 27, 2006

Posted by jtintle in Planets, Space News.
Tags: , , , , , , ,

Well I don’t usually write posts for this site, but with all the coverage of Pluto’s demotion to dwarf planet, I thought I would chime in with my opinion.

Three days ago in Prague, the International Astronomical Union voted on and passed a new definition of Planets, which demotes Pluto to a new classification of Dwarf Planet. The actually definition for a Planet is:

A “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) shape, and (c) has cleared the neighbourhood around its orbit.

Which means our solar system is now made up of 8 planets, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

The IAU also defined a new classification: a dwarf planet. The formal definition is:

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) shape , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

Which means Pluto, Ceres and 2003 UB313(nicknamed Xena) are the first dwarf planets. The IAU also defined all other objects except satellites orbiting the Sun shall be referred to collectively as “Small Solar-System Bodies”. The actual press release is here.

Now I have been reading articles and blog posts objecting to the demotion of Pluto from full Planet status. I just have to ask why are people objecting to this change? Is it because most people are afraid of change? The people who should be really upset are the people working on and with the New Horizons spacecraft. These hard working people finally had their spacecraft lift off in January of this year, at the time headed for the ninth planet, now it is headed for the first Dwarf Planet. The real reason they should be upset, is when budget time comes around they will have to fight with the politicians to keep funding flowing to their project to a dwarf planet. You already know the Senators and Congressmen are not going to like the idea of spending more money on something that isn’t a planet.

An Artist's View of the Pluto System
My opinion is this, the IAU made a decision, voted on and passed by their members. These members are probably some of the most knowledgeable people on the planet to make this decision. Our knowledge of the Universe and especially our Solar System is growing, so why can’t our classifications change also. Remember when people said the world was flat, and the uproar that was caused by saying it was round, or the uproar surrounding the idea that Earth orbited the Sun and not the other way around. At least with this reclassification no one is being killed for their beliefs. Anyway this classification can change in the future, depending what data the New Horizons spacecraft send back to earth. Pluto hasn’t even been called a planet for a hundred years yet, so what is the big deal. Anyway I hope the outrage subsides and we can get back to learning more about the universe we live in.

Image Credit:

NASA, ESA and G. Bacon (STScI)


I’ve been doing some additional surfing and ran across this little post about Pluto: Requiem for the 10th (and 9th) planet(s)


1. Zachary Drake - August 27, 2006

Thanks for the link. (I’m the author of the post you link to in your update.) I’m glad to hear your voice added to the chorus of acceptance to this new classification system. It makes sense, and should be extendable to other solar systems.

2. Pron - August 30, 2006

Hi! Thanks for the link.

3. david - September 11, 2006

I think it is kinda stupid pluto might not be a planet any more.

4. Brandon Sather - September 11, 2006

im really gay im fone # is 669-7100

5. Brandon Sather - September 11, 2006

im kidding

6. amadiyah - June 11, 2008

ufo’s are real

7. Sophia Cardines - March 7, 2009

do you have any pictures of pluto from space?
or actual pictures for pluto?

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