Comparative analyses of two Jupiter family comets: dust-rich 67P/Churyumov-Gerasimenko and dust-poor 2P/Encke O. Ivanova The results of imaging photometric, polarimetric, and long-slit spectroscopic observations of comet 67P/Churyumov–Gerasimenko in 2015–2016, which was the target of the ESA’s Rosetta mission, and a highly evolved comet 2P/Encke in apparitions of 2013 and 2017 are presented. Similar radial variations of polarization and color over the coma revealed in both comets, dust-poor comet Encke and dust-rich comet 67P/C-G, are discussed. Revealed radial variations of polarization and color in both comets, dust-poor comet Encke and dust-rich comet 67P/C-G, suggest a change in the particle properties and, hence, in the mean scattering properties of the grains on a time-of-flight timescale.