Heat flux observations and the location of the transition region boundary of Giacobini‐Zinner

Electron heat flux observations and associated plasma phenomena upstream from comet Giacobini‐Zinner show many similarities to observations upstream from the Earth's magnetosheath. Two similarities are discussed. Heat flux events are used to compute the transition region boundary location. The computed subsolar standoff distance of 4×10 4 km is commensurate with a comet gas production rate, G, of 3×10 28 molecules/s (mol/s), in accord with ground‐based determinations of G.