Revealing the Universe In this session, speakers will describe some of the exciting results from Herschel that touch on all aspects of  the life cycle of matter in galaxies. The interstellar medium (ISM) plays a central role in the evolution of galaxies as the birth site of new stars and the repository of old stellar ejecta. The formation of new stars slowly consumes the ISM, locking it up for millions to billions of years. As these stars age, the winds from low mass, asymptotic giant branch stars and high mass, red supergiants, and supernova explosions inject nucleosynthetic products of stellar interiors into the ISM, slowly increasing its metallicity. This constant recycling and associated enrichment drives the evolution of a galaxy’s visible matter and changes its emission characteristics. Dust and molecules are present during the key transition points of matter in galaxies. Interstellar dust exists well mixed with atomic and molecular gas in the ISM. Dust and molecular gas enshrouds young stellar objects, the most recently formed stars. The dusty molecular winds of dying stars and explosive supernovae eject dust into the ISM. Dust and molecules emit radiation in the far-infrared and submillimeter wavelengths of the Herschel Space Observatory, a European Space Agency–led mission with significant collaboration from the National Aeronautics and Space Administration (NASA) and the Canadian Space Agency.