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Old 11-October-2006, 05:02 AM
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kheider kheider is offline
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Originally Posted by Planet X View Post
The term "Minor Planet" has officially been ditched as a reference to small bodies, I'd suggest that they revive the term to refer to bodies in the 2000-6000 km diameter range.
The term minor planets was renamed to SSSB (Small Solar System Bodies) so that people would not consider them as a true subset of planets. I agree that it is strange that the term 'dwarf planets' (compound noun) is currently in use but the term can can be renamed later.

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Originally Posted by Planet X View Post
1. Major Planet - (a) is above 6000 km in diameter
This removes Mercury as Major Planet even though Mercury has been known as a Planet (wanderer in the sky) for thousands of years. Current theory even suggests that Mercury may even have been a Cthonian Planet due to its high density and metal-rich core.

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Originally Posted by Planet X View Post
(e) has definitely cleared the neighborhood around its orbit (with the legitimate exception of Trojan Bodies).
Just change the current IAU definition to say: "and (c) dominates the neighborhood around its orbit clearing it of comparable objects"

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Originally Posted by Planet X View Post
2. Minor Planet - (a) is 2000-6000 km in diameter
When people can't even agree on Planets vs 'Dwarf Planets' you want to create an arbitrary 3rd grouping?

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Originally Posted by Planet X View Post
3. Planetoid - has insufficient mass to have a differentiated interior
Asteroid Vesta (580km in dia) has a differentiated interior.

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Originally Posted by Planet X View Post
4. Planetesimal - basically potato-like (irregular) shape
Those are already called asteroids. The term "Planetesimal" is already in general use.

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Originally Posted by Planet X View Post
it would give future generations the possibility of actually finding a new planet.
Even with the current IAU definition of a Planet there is a decent chance of finding a Planet beyond the Kuiper Belt.

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Originally Posted by Planet X View Post
Besides, it's highly unlikely the number of bodies above 2000 km in diameter will skyrocket to ridiculous numbers anytime soon, even out to several hundred AU distant.
And this is the part of the reason that objects under 2000km in diameter AND large enough to be spherical, BUT ARE NOT DOMINANT in their region, are considered 'dwarf planets'.

If you don't like calling Pluto a dwarf planet, call it a planetoid, protoplanet, or a 'minor planet' if you want to.

-- Kevin Heider
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