Simulation models play an important role in decision making and developement of new scientific theories. In view of their critical role, everyone can expect complete and relevant information about the confidence level that are associated with them. To achieve this goal, we must perform validation and verification (V&V) operations. This represents an important challenge in Earth Faculté des sciences where modelized systems are complex and open. An anthropic night-sky radiance model was studied to establish a V&V strategy that might be applied to Earth Faculté des sciences models in general. This strategy include qualification (are we modeling the right phenomenon?), verification (does implemantation respect the specifications?), and validation (does software simulate the phenomenon correctly?). Qualification and verification show the relevance of the selected governing equations and allow us to identify paths to improve software management maturity. Effects of distance and angle of view on anthropic night-sky radiance were studied in validation. Comparison of simulations and measurements show interesting similarities