Liv Hornekær is assistant professor at The Department of Physics and Astronomy, University of Århus. Her main research interest is experimental studies of surface reactions under interstellar conditions. Her work has focused on identifying the atomic scale mechanisms behind interstellar H2 formation by combining a broad range of surface science techniques, e.g Scanning Tunneling Microscopy, Temperature Desorption Spectroscopy, Laser desorption and time of flight techniques. Her major contributions to the field have been to uncover the relevant reactions on the atomic level and to identify the importance of the dust grain surface morphology for the energy release in H2 formation.