Planet formation

Prof. Gerhard Wurm’s research group has conducted a series of studies exploring the first phases of the formation of terrestrial planets and interactions between the atmosphere of Mars and its surface. Two examples of this work deserve special mention. In a novel experiment, the researchers succeeded in determining the forces and for the first time also the torques effective in contact between nanometre-sized ice particles. This information provides a basis for modelling the growth of larger aggregates, ranging from fractals to more compact structures.

In another highlight, the researchers proved for the first time in microgravitation experiments in the drop tower in Bremen that thermal creep in the gas under low pressure on the surface of Mars causes a large area of that dust-covered ­surface to act like a pump, conveying gas from the surface and into the atmosphere in warm, sunlit areas and sucking it back in again in shaded areas. This alters interactions between the surface and volatile components (e.g. water). The mechanism was unknown to date.