Celestia is a three-dimensional space simulator. Simulation of the space allows exploring our universe in three dimensions. Celestia is available on Windows, Linux and macOS. The project is very small and PVS-Studio detected few defects in it. Despite this fact, we'd like to pay attention to it, as it's a popular educational project and it will be rather useful to somehow improve it. By the way, this program is used in popular films, series and programs for showing space. This fact, in turns, raises requirements to the code quality.