Bye bye Pluto

[Garry.W]

Overnight, poor old Pluto has been stripped of its status as a planet when astronomers from around the world redefined it as a "dwarf planet", leaving just eight major planets in the solar system

With one vote all the toys and models of the solar system become instantly obsolete. I feel for all the teachers and publishers who now have to scramble to update textbooks and lessons used in classrooms for decades. What about trivial pursuit? You're buggered if you get that question about naming all the planets in our solar system.

As one ten-year old put it, "Is this is what you get for naming a planet after a disney character?" - only an American kid could come up with that one

Whole thing a bit Mickey Mouse if you ask me

[ManDownUnder]

I say sue them...

Actually... and seriously... remind me how this is part of the scientific process? What criteria does an orbital body need to meet (or not meet) in order to be a planet.

If it meets those criteria... then by definition it's either a planet or not...

Or where they voting on those criteria?

edit - a 1/2 way decent write up is here

[SARGE]

Overnight, poor old Pluto has been stripped of its status as a planet when astronomers from around the world redefined it as a "dwarf planet", leaving just eight major planets in the solar system

With one vote all the toys and models of the solar system become instantly obsolete. I feel for all the teachers and publishers who now have to scramble to update textbooks and lessons used in classrooms for decades. What about trivial pursuit? You're buggered if you get that question about naming all the planets in our solar system.

As one ten-year old put it, "Is this is what you get for naming a planet after a disney character?" - only an American kid could come up with that one

Whole thing a bit Mickey Mouse if you ask me

didnt they just find one farther out and name it Xena?

to be called a planet, a celestial body must be in orbit around a star while not itself being a star.

It must be large enough in mass for its own gravity to pull it into a nearly spherical shape and have cleared the neighborhood around its orbit.

Pluto was disqualified because its oblong orbit overlaps Neptune's. Xena also does not make the grade of being a planet, and will also be known as a dwarf planet.

[James Deuce]

Settle!

You have to remember the origin of the word planet and its original definition as objects that move about in the night sky against the background of the immovable stars.

What has happened in the last decade or two has been the discovery of a vast number of Kuiper belt objects in a Trans Neptunian orbit around the Sun. Some of these objects are larger than Pluto.

Our definition of planet has changed from lights in the sky to solid objects or Gas Giants that orbit a star around the plane of the ecliptic without crossing the orbit of another planet. I am sure that the definition will be improved by adding dimension and gravitational field parameters and so on until the label is meaningful from our new context of understanding.

The definition of planet has changed from connotative to dennotative as we have developed tools to "see" planets and define how they relate to a "Solar System".

[Sniper]

They have no right to just suddenly change it.

[James Deuce]

I say sue them...

Actually... and seriously... remind me how this is part of the scientific process? What criteria does an orbital body need to meet (or not meet) in order to be a planet.

If it meets those criteria... then by definition it's either a planet or not...

Or where they voting on those criteria?

edit - a 1/2 way decent write up is here

There are no criteria, that's the problem. The debate over what defines planetary body has only started in the last decade.

[skelstar]

So does Pluto cross Neptune's orbit, or is it vice-versa?

[James Deuce]

So does Pluto cross Neptune's orbit, or is it vice-versa?

Pluto crosses Neptune. It also rises above and below the plane of the ecliptic. Neptune is the last planetary sized object with a stable orbit. It's magnetic poles point off in funny directions though. Most of the other planets have magnetic poles within 25 degrees of the plane of the ecliptic.

[ManDownUnder]

There are no criteria, that's the problem. The debate over what defines planetary body has only started in the last decade.

I was just reading about it (other pages on the link I posted above). Bloody interesting actually...

[SARGE]

the latest definition

[Motu]

I always thought Pluto looked a bit like Goofy,y'know...like ''cousins'' or something.I'd be really pissed off if they stripped Goofy of his place in my system...

[Garry.W]

didnt they just find one farther out and name it Xena?

Right you are Sarge. Mike Brown of the California Institute of Technology, discovered UB313 in 2003 and it was nicknamed Xena. It is larger than Pluto, and instantly created a buzz over whether a new planet had been discovered.

However, the definition of a planet, approved after a heated debate among 2,500 scientists from the International Astronomical Union (IAU) meeting in Prague, drew a clear distinction between Pluto and the other eight planets.

The need to define what is a planet has been driven by technological advances enabling astronomers to look further into space and measure more precisely the size of celestial bodies.

The significance is that new discoveries and new science have told astronomers that there is something different about Pluto from the other eight planets and as science learns more information, they get new results and new considerations.

All the scientists agreed that, to be called a planet, a celestial body must be in orbit around a star while not itself being a star. It must be large enough in mass for its own gravity to pull it into a nearly spherical shape and have cleared the neighborhood around its orbit.

Pluto was disqualified because its oblong orbit overlaps with Neptune's. Xena also does not make the grade of being a planet, and will also be known as a dwarf planet.

Funnily enough if the agreed-upon definition -- the first time the IAU has tried to define scientifically what a planet is -- actually ended up being that discussed in a draft paper sent to delegates at the General Assembly last week, Pluto would still be a planet and three others would have been added.

But, the new definition creates a second category called "dwarf planets", as well as a third category for all other objects, except satellites, known as small solar system bodies. Really, the sceintists have expanded the number of planets in our solar system, but just spread them over two categories.

So the answer to the trivial pursuits question will be Mercury, Venus. Earth, Mars, Jupiter, Saturn, Uranus and Neptune

[Swoop]

I do not like it at all.

This will start an intergalactic war! (and the space shuttle is dodgy enough already...)

[Ghost Lemur]

Wired also had a good write up on the debate.

Very interesting stuff.

It does remind you that all our definition, categories, measures, etc, are man made and therefore falible.

[SARGE]

Wired also had a good write up on the debate.

Very interesting stuff.

It does remind you that all our definition, categories, measures, etc, are man made and therefore falible.

Science is an ever-evolving process also GL.. only 500 years ago prior to the the Copernican theory ,the world was flat and at the center of the universe..

black holes, wormholes and dark matter are very recent discoveries..

is WARP drive far off ?


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