Rosetta measures comet's temperature The first temperature measurements of comet 67P/Churyumov-Gerasimenko were made when Rosetta closed in from 14000 km to the comet to just over 5000 km. The observations were made by the spacecraft's visible, infrared and thermal imaging spectrometer, VIRTIS, and revealed an average surface temperature of -70ºC. This implies the surface is predominantly covered in dust rather than ice, which would yield a lower temperature. The finding does not exclude localised patches of ice. The observations were made when the comet was ~553.5 million km from the Sun.