Comets belong to the most pristine objects in our solar system. The study of these small icy bodies reveals crucial information about the material present during solar system formation and the physical and chemical conditions at the time and location of formation. Investigating their composition is thus a crucial step in the understanding of our own origins.

A few comets have been visited by spacecraft and many more have been observed from ground. The Stardust mission even brought a sample of cometary dust back to Earth for in-depth analysis. Recently, the European Space Agency's Rosetta spacecraft competed its mission. The spacecraft accompanied comet 67P/Churyumov-Gerasimenko along its trajectory past the sun from August 2014 to September 2016. Rosetta carried several instruments to investigate the comet's nucleus and surrounding neutral gas, dust, and plasma environment.

In this presentation we will address some of the major findings of the Rosetta mission in terms of the composition of volatiles of 67P/Churyumov-Gerasimenko and discuss the implications on the formation and thermal evolution of the comet. We will review the results in the light of observations obtained at other comets and extend the comparison beyond our solar system to ices and volatiles detected around newly forming stars and in the interstellar medium.