This work is based on observations from ALMA, a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in co-operation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. Data from ROSINA, an instrument part of Rosetta mission, were used in this work. Rosetta is a European Space Agency (ESA) mission with contributions from its member states and NASA, and we acknowledge herewith the work of the whole ESA Rosetta team. E.C.F. and K.I.O. acknowledge financial support from the Simons Foundation (SCOL award 321183, KO) and to Northrop Grumman Corporation. The group of J.K.J. acknowledges support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 646908) through ERC Consolidator Grant S4F. Research at the Centre for Star and Planet Formation is funded by the Danish National Research Foundation. Work at the University of Bern was funded by the State of Bern, the Swiss National Science Foundation, and the ESA PRODEX programme (Programme de Développement d’Expériences scientifiques). E.F.v.D. acknowledges A-ERC grant CHEMPLAN 291141. M.N.D. acknowledges the financial support of the Center for Space and Habitability (CSH) Fellowship and the IAU Gruber Foundation Fellowship. S.F.W. acknowledges financial support from a CSH fellowship.