[en] The viscosity of high pressure ice VI has been measured at room temperature and pressures of 1.1 to 1.2 GPa giving a value of approximately equal to 1014P which suggests that solid state convection might have taken place during the early evolution of Ganymede, thus preventing melting and differentiation. Measurements were carried out in a sapphire anvil cell using fine particles to visualize the flow of ice down the radial pressure gradient. (U.K.)