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Re: Mass, Size Requirements

On Tue, 11 Mar 1997, Paul Harris wrote:

> Jerry asks:
> What is the mass or size requirement to be called the following:
> Asteroid  -
> Planetoid -
> Meteoroid - 
> You may send your answer to paul@meteorite.com - Thanks!
I do not think that there is a mass constraint on the above designations. 
I think that the way to look at those designations is as 
follows(planetary geologists forgive me if I dilute too much):\

1. Planetoid: This refers to planetary sized objects.These are bodies 
that have a large diameter(this size is subjective,but some where around 

2. Asteroid: This refers to objects found only in the asteroid belt, or 
that have orbits that can be traced back to the belt. This is purely a 
conventional term, and has no genetic signifigance what so ever as far as 
I can tell. Perhaps an asteroid specialist would argue otherwise. 

3. Meteoroid: This term is purely descriptional. It refers to any object 
that has not penetrated the Earth's atmosphere. For example, an Earth 
crossing asteroid is a meteoroid, no matter how large it is. If it hits 
the atmosphere, it is a meteor, and if it hits the Earth, it is a meteorite.

	So as you can see, these are for the most part, descriptive terms 
about an object, without a genetic signifigance. Some specialists would 
argue otherwise, I am sure, but I cannot see any true distinction between 
the above terms as related to mass,and composition. Perhaps someone would 
argue the point? I would be interested in hearing about it.

Frank Stroik
University of Wyoming