[meteorite-list] Earth's Surface Transformed by Three MassiveAsteroid Impacts 3.2 Billion Years Ago

[tracy latimer]

Someone please refresh my memory -- about how long ago was the theorized 
impact that tore loose the Moon from the proto-Earth?  This sounds like it 
happened after the Moon had coalesced enough to be a single solid.

Tracy Latimer

>From: Ron Baalke <baalke at zagami.jpl.nasa.gov>
>To: meteorite-list at meteoritecentral.com (Meteorite Mailing List)
>Subject: [meteorite-list] Earth's Surface Transformed by Three 
>MassiveAsteroid Impacts 3.2 Billion Years Ago
>Date: Fri, 5 Aug 2005 11:47:36 -0700 (PDT)
>
>
>http://info.anu.edu.au/mac/Media/Media_Releases/_2005/_August/_050805glikson.asp
>
>Earth's surface transformed by massive asteroids
>Australian National University media release
>August 5, 2005
>
>A cluster of at least three asteroids between 20 and 50 kilometres
>across colliding with Earth over 3.2 billion years ago caused a massive
>change in the structure and composition of the earth's surface,
>according to new research by ANU earth scientists.
>