Hans-Peter Gail received his PhD in astrophysics from the University of Heidelberg, Germany, where he has been a professor since 1996. His research interests include cosmic dust, the cosmic matter cycle, mass-loss processes, protoplanetary disks and astromineralogy. Erwin Sedlmayr is a Professor of Astronomy and Astrophysics at the Technische Universität Berlin, Germany, where he served as the head of the Center for Astronomy and Astrophysics for seven years. His research focuses on cosmic dust, modeling stellar dust forming systems, stellar mass-loss, the cosmic matter cycle and non-linear dynamics.