Two articles published in the journal “Science” describe the discovery of dry ice, meaning frozen carbon dioxide, on the surface of the comet 67P/Churyumov-Gerasimenko. A team of researchers led by Gianrico Filacchione of the Italian National Institute for Astrophysics and another led by Sonia Fornasier the French LESIA-Observatoire de Paris and Université Paris Diderot used the observations conducted with the VIRTIS spectrometer aboard ESA’s Rosetta space probe to find for the first time dry ice on a comet’s nucleus.