Summary of the direct inversion technique. Left panel: jets are identified in two different images, only one is shown here, see Fig. A.2 for the full sequence. Middle panel: triangulation, for each image we know the precise position and attitude of the spacecraft. From this we define the planes of jets (spacecraft, line of sight, observed jet direction). The intersection between these planes defines the jet in three dimensions, and we calculate their intersection with the surface. Right panel: knowing sources and directions, plus some assumptions on grain velocity, we can reconstruct the jets trajectories (yellow lines).