Dielectric and conducting objects have natural frequencies of oscillation in the electromagnetic spectrum. The location of these natural frequencies in the complex-frequency plane is dependent upon the physical characteristics of each particular object. Spherical dielectric objects have a particularly well-ordered resonance structure. The solution of the scattering problem for spherical resonators uses the standard separation-of-variables approach. There is also interest in determining the scattering characteristics of near-spherical objects both for studies of resonant behavior and to analyze the propagation of electromagnetic waves (at microwave, millimeter and optical frequencies) through the atmosphere. The T-matrix method can be used for such calculations.