[meteorite-list] Observed lunar meteorite impacts hit 100

[Chris Peterson]

There are clearly two very distinct populations of objects, which have 
very different properties. Comets originate in the outer edge of the 
Solar System, and ices account for a significant proportion of their 
entire mass. Very few ever make it to the inner system, and when they 
do, they can usually be identified by their high eccentricity orbits. 
Asteroids are differentiated rocky or iron bodies that were formed or 
trapped in orbit between Mars and Jupiter.

It is quite correct to distinguish between the two types of bodies. The 
confusion comes from the likelihood that some comets have ended up in 
asteroidal orbits, and have lost their volatiles. And also, that 
gravitational perturbations have put some asteroids into more comet-like 
orbits. It isn't that these aren't very different objects, but that in 
some cases we are uncertain about an object's true classification. 
Additionally, we know little about composition. A burned out comet may 
or may not be similar to an asteroid from a mineralogical standpoint.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message ----- 
From: "Mark Ford" <mark.ford at ssl.gb.com>
To: <Meteorite-list at meteoritecentral.com>
Sent: Thursday, May 22, 2008 3:42 AM
Subject: Re: [meteorite-list] Observed lunar meteorite impacts hit 100

> Good point Larry.
>
> But I can't understand why people are still carefully distinguishing
> between comets and Asteroids?, I think by now we can assume they are
> basically one and the same, and not some exotic different species. To 
> me
> it's just that some rocks are more 'wet and oily' than others...
>
> I'd find it very very hard to believe there are no pieces of comet in
> our collections.
>
> Best,
> Mark Ford
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