Disposition of the Peak 1 and Peak 2 objects in yellow and green, respectively at the epoch time zero of the explosion seen in the line-of-sight (i.e. perpendicular to the plane of the sky xy). Thirty-six features are displayed in this figure. The dark dot is the computed expansion center (Nissen 2008; Bally et al. 2011). The ring-like structure which forms when proper motions are run backward in time is highlighted in violet. This structure is the starting point for the 3D-simulations illustrated in subsequent figures. Units are in arcseconds.