You're unlikely to get good images from indoor viewing. Having the scope at the same temperature as the environment is important for high magnification, and having thermal air currents (inevitable through an open window, given that your house has very different air from the outside) is guaranteed to fuzz your vision. The moon requires lower magnification and hence probably looks better.
Professional observatories go to great lengths to keep the scope and its surroundings at the same temperature as the outdoors. The floor around the scope at large observatories may have built-in cooling coils, for example.
Go outside, let the scope cool to the ambient temperature, let the planets rise well above the horizon, and try again.