Why aqueous alteration in asteroids was isochemical: High porosity ≠ high permeability - Bland,PA; Jackson,MD; Coker,RF; Cohen,BA; Webber,JBW; Lee,MR; Duffy,CM; Chater,RJ; Ardakani,MG; McPhail,DS; McComb,DW; Benedix,GK (EARTH AND PLANETARY SCIENCE LETTERS, 2009)