An autonomous navigation system may autonomously navigate a vehicle through an environment in which one or more non-solid objects, including gaseous and/or liquid objects, are located. Sensors, including sensors which can detect chemical substances in a region of the environment, may detect non-solid objects independently of an opacity of the objects. Non-solid objects may be determined to present an obstacle or interference based on determined chemical composition, size, position, velocity, concentration, etc. of the objects. The vehicle may be autonomously navigated to avoid non-solid objects based on positions, trajectories, etc. of the non-solid objects. The vehicle may be navigated according to avoidance driving parameters to avoid non-solid objects, and a navigation system may characterize a non-solid object as a solid object having dimensions and position which encompasses the non-solid object, so that the vehicle is navigated in avoidance of non-solid objects as if the non-solid objects were solid.