[meteorite-list] The (Long) Weekend Warrior: ... Crater Size and Age

[MEM]

With regard to the range of asteroid sized bodies, average body size is trending 
smaller owing to collisions.  The solar system has been greatly depleted of 
larger bodies as compared to the original populations of planetary/asteroidal 
bodies. Collisions, by-in-large, produce multiple "smaller" objects which, over 
time, produce even smaller objects and so on.  So large impacts "statistically" 
point back to a very early solar system with a greater  proportion of  larger 
objects.  The impact itself is evidence of depletion.

In general, the more impacts  visible on the surface, the relatively longer 
exposure that surface has had to impacts.  An older surface that hasn't been 
renewed by tectonic/volcanic recycling will have more craters and a higher 
proportion of  larger astroblemes.  We date planetary surface geological 
activity/age using crater count and overlap statistics with crater sizes 
factored in..

Elton



----- Original Message ----
> From: Jonathan E. Dongell <jdongell at cox.net>
> To: Ron Baalke <baalke at zagami.jpl.nasa.gov>; Meteorite Mailing List 
><meteorite-list at meteoritecentral.com>
> Sent: Tue, October 19, 2010 9:41:26 PM
> Subject: Re: [meteorite-list] The (Long) Weekend Warrior: Nine Moons, 62 Hours 
>(Cassini)
> 
> Ron,
> I can understand why more impacts could be an indication of an older  
>satellite,
> but could you explain why 'larger' impacts is also an indication  of older, as 
>well.
> Thank you, in advance.
> Jonathan Dongell
> IMCA  3922