ERC Advanced Grant Project ‘Ground-Truth for Pebbles’: Unique laboratory experiment to study planetary formation in Braunschweig

Professor Jürgen Blum from the Institute of Geophysics and Extraterrestrial Physics at Technische Universität Braunschweig and his team are playing a central role in the ERC Advanced Grant project ‘Ground-Truth for Pebbles’, or GT4Pebbles for short. Together with Professor Carsten Dominik from the Anton Pannekoek Institute for Astronomy at the University of Amsterdam, he is investigating how tiny dust particles grow into larger aggregates and condense – forming so-called pebbles – to eventually become planets.

A particular focus is on the question of whether pebbles, compact particles measuring between a millimetre and a centimetre in size, can form in sufficient quantities and with the right properties to enable subsequent planet formation in a sustainable manner. To answer this question, Professor Blum and his team will set up a laboratory experiment that is unique worldwide. A rotating vacuum chamber with a diameter of 2 metres and a weight of 5 tonnes, filled with a thin gas, will simulate the conditions in a forming planetary disc. In this chamber, the processes of growth and compaction of the dust grains will be observed live and the properties of the growing and ultimately compacting aggregates will be measured. Over the next five years, these experiments will help to establish an empirical foundation for planetary formation models.

The huge vacuum apparatus is being built by Pfeiffer Vacuum Components & Solutions GmbH in Göttingen and is scheduled for delivery to the Technical University of Braunschweig at the end of March 2026. Subsequently, the numerous diagnostic devices required, such as cameras, a light scattering unit and a spectrometer, must be integrated into the system.

Scientific operation is then scheduled to begin in October 2026.