This paper provides a brief overview of the journey of molecules through the Cosmos, from local diffuse interstellar clouds and PDRs to distant galaxies, and from cold dark clouds to hot star-forming cores, protoplanetary disks, planetesimals and exoplanets. Recent developments in each area are sketched and the importance of connecting astronomy with chemistry and other disciplines is emphasized. Fourteen challenges for the field of Astrochemistry in the coming decades are formulated.

This brief overview stresses the importance of molecular processes in modern astrophysics and provides examples where the availability of new laboratory or theoretical data proved crucial in the analysis. This includes basic data such as spectroscopy and collisional rate coefficients, but also an improved understanding of reactions and photoprocesses in the gaseous and solid state. In spite of many lingering uncertainties, the future of molecular astrophysics is bright with new facilities such as ALMA, JWST and ELTs on the horizon. Together, they will allow increased understanding of the journey of gas and solids from clouds to stars and planets, and back to the interstellar medium.