Mike Jr wrote:
"All of Ganymede's rock sank to its center the same way that all the
chocolate chips sink to the bottom of a melted carton of ice cream."
http://www.nature.com/ngeo/journal/v...s/ngeo746.html

--Mike Jr.

Adding sci.astro to the list.

So why exactly would Ganymede be bombarded heavily but not Callisto?

Yousuf Khan