Calculated lithospheric strength envelopes (s) are rheological models of the lithosphere that are useful in understanding the elastic () and seismogenic () thicknesses of the lithosphere. Determinations of Te for Mars using different techniques use different models of Te as indicated by rheology in LSEs, and LSEs indicate that the differential stress fields that cause deformation must be considered in the determination of both Te and Ts. We do not attempt to review the literature here or to rank different methods. Our goal is to provide a better understanding of the different values of Te and Ts published in the literature and to encourage integration of these data with a physical understanding of the lithosphere in time and space.