Illustration of the plasma interaction boundaries that have been observed at more than one of the comets listed in Table 1 (not to scale). The boundaries are as follows: bow shock (red solid line), cometopause (orange dashed line), cometary ion collisionopause (green dash-dot line), ion pileup (blue dash-dash-dotted line), and diamagnetic cavity boundary (purple solid line). Observed distances where applicable are listed in Table 1 for four comets. The gray shaded region is the portion of the comet solar wind interaction explored by Rosetta between May and December 2015. This is a schematic and does not accurately represent the shape of the boundaries. For instance, the diamagnetic cavity boundary seems to be more structured than this simplified view shown here in violet (e.g., Henri et al. 2017).