Out You Go Pluto, and this is the reason why...

[Suzy]

An explanation on what makes a planet a planet - and errr..., Pluto not.


http://http://www.universetoday.com/13573/why-pluto-is-no-longer-a-planet/

If I'm to share my opinion, I would have to say, no, I don't think Pluto should be given planetary status.

Other reasons aside, memorising the 70,000 other "planets" (icy objects that have shown to be similar to Pluto out in the Kuiper belt) could be a toughy.

Is Pluto a planet? Does it qualify? For an object to be a planet, it needs to meet these three requirements defined by the IAU:

• It needs to be in orbit around the Sun – Yes, so maybe Pluto is a planet.
• It needs to have enough gravity to pull itself into a spherical shape – Pluto…check
• It needs to have “cleared the neighborhood” of its orbit – Uh oh. Here’s the rule breaker. According to this, Pluto is not a planet.

What does “cleared its neighborhood” mean? As planets form, they become the dominant gravitational body in their orbit in the Solar System. As they interact with other, smaller objects, they either consume them, or sling them away with their gravity. Pluto is only 0.07 times the mass of the other objects in its orbit. The Earth, in comparison, has 1.7 million times the mass of the other objects in its orbit.

[mswhin63 (Malcolm)]

I agree it for the de-classifacation. I think it was only considered a planet because first observation saw it as almost the size of the earth.

I also heard that ever so possible it could be considered a Comet. Mainly because it has a tail.

I think we will have to wait till the probe gets there to confirm a lot of things

[supernova1965 (Warren)]

Originally Posted by mswhin63

I agree it for the de-classifacation. I think it was only considered a planet because first observation saw it as almost the size of the earth.

I also heard that ever so possible it could be considered a Comet. Mainly because it has a tail.

I think we will have to wait till the probe gets there to confirm a lot of things

Pluto has enough mass to form a globe and the definition of a planet is below and comets dont form a globe so how can it be classed as a comet.

A celestial body moving in an elliptical orbit around a star.Wikipedia dictonary

Even this definition still calls it a Dwarf planet so still refered to as a planet even if it is a small one

IAU definition of planet

From Wikipedia, the free encyclopedia
This article is about the formal definition established in 2006. For prior usage, see Definition of planet.
The definition of planet set in 2006 by the International Astronomical Union (IAU) states that in the Solar System a planet is a celestial body that:

1. is in orbit around the Sun,
2. has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and
3. has "cleared the neighbourhood" around its orbit.

A non-satellite body fulfilling only the first two of these criteria is classified as a "dwarf planet". According to the IAU, "planets and dwarf planets are two distinct classes of objects". A non-satellite body fulfilling only the first criterion is termed a "small solar system body" (SSSB). Initial drafts planned to include dwarf planets as a subcategory of planets, but because this could potentially have led to the addition of several dozens of planets into the Solar System, this draft was eventually dropped. In 2006, it would only have led to the addition of three (Ceres, Eris and Makemake) and the reclassification of one (Pluto). The definition was a controversial one and has drawn both support and criticism from different astronomers, but has remained in use.
According to the definition, there are currently eight planets and five dwarf planets known in the Solar System. The definition distinguishes planets from smaller bodies and is not useful outside the Solar System, where smaller bodies cannot be found yet. Extrasolar planets, or exoplanets, are covered separately under a complementary 2003 draft guideline for the definition of planets, which distinguishes them from dwarf stars, which are larger.

Going by the above definition there are actually 13 planets because it defines 5 dwarf planets

[richardda1st (Richard)]

Read all about it.
Get all the 'good' facts. Don't walk but BOLT straight to this site

http://uncyclopedia.wikia.com/wiki/U...onger_a_Planet


ps Don't forget to take your nuts along.

[renormalised (Carl)]

If you follow the IAU's "accepted" definition of what a planet is, then none of the "planets" of our Solar System can be called a planet. Not a single one of them, including Jupiter, has cleared its orbit of miscellaneous debris. What about all the Trojan asteroids, the NEO's, the Aten objects, the short period comets, the Centaur asteroids/comets etc etc etc.

The IAU definition is marginal at best and wasn't even taken with barely a quorum of members of the Union present. It was rushed through right at the end of the last Union conference when most of the delegates had left. Most of those present there then were supporters of the new definition to begin with.

[michaellxv (Michael)]

Originally Posted by renormalised

If you follow the IAU's "accepted" definition of what a planet is, then none of the "planets" of our Solar System can be called a planet. Not a single one of them, including Jupiter, has cleared its orbit of miscellaneous debris. What about all the Trojan asteroids, the NEO's, the Aten objects, the short period comets, the Centaur asteroids/comets etc etc etc.

Is the actual wording 'cleared'? I thought I saw it once as 'dominated its orbit' which is different and would make them planets again.

Also, by rule #1 there can be no planets around other stars as they are not 'The Sun'. Or has this wording been misquoted also?

[renormalised (Carl)]

Cleared....never was dominated.

Good point

[Barrykgerdes]

All the controversy has got nothing to do with astronomy, solar systems, planets etc. It is all about some hopeful scientist/astronomers getting their names to the forefront in the hope of new appointments and MORE MONEY.

Barry

[astroron (Ron)]

Originally Posted by Barrykgerdes

All the controversy has got nothing to do with astronomy, solar systems, planets etc. It is all about some hopeful scientist/astronomers getting their names to the forefront in the hope of new appointments and MORE MONEY.

Barry

What all 400 or so who voted in favour of the change,who is going to give them more money and Jobs just because they changed the deffinition of a solar system body:screwy :
Cheers

[noswonky (Peter)]

The following video clearly explains the whole Pluto issue:

http://www.youtube.com/watch?v=Ii75DczWVCs