Some theories of Jovian decametric and Terrestrial kilometric radiations require that the emissions escape at the plasma frequency in the magnetospheres of these planets. This requirement creates difficulties in explaining a number of characteristics of these radiations. It seems that the problems may be overcome by invoking wave--wave interaction between Z-mode waves, and it is suggested that an estimate of Saturn's magnetic field on the basis of the observed hectometric radiation could be erroneous. |