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

From: Jonathan E. Dongell <jdongell_at_meteoritecentral.com>
Date: Tue, 19 Oct 2010 22:48:09 -0700
Message-ID: <001b01cb701a$60b55bf0$6401a8c0_at_homepc>

Got it.
Thanks Elton.


----- Original Message -----
From: "MEM" <mstreman53 at yahoo.com>
To: "Jonathan E. Dongell" <jdongell at cox.net>; "Meteorite Mailing List"
<meteorite-list at meteoritecentral.com>
Sent: Tuesday, October 19, 2010 10:08 PM
Subject: Re: [meteorite-list] The (Long) Weekend Warrior: ... Crater Size
and Age


> 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
Received on Wed 20 Oct 2010 01:48:09 AM PDT