In the last decade, groundbreaking discoveries with high angular resolution facilities like ALMA and SPHERE revealed the rich sub-structure of planet-forming disks on tens of au spatial scales. However, the inner region of disks (r < 10 au), the birthplace of terrestrial planets, has remained relatively unexplored. Currently, infrared interferometry with facilities like ESO's Very Large Telescope Interferometer (VLTI) is the only technique to get spatially resolved information on that area. The VLTI/MATISSE Guaranteed Time Observations team, which I am part of, is conducting a multi-year large survey of about a hundred planet-forming disks, with the aim to create a systematic overview of inner disk sub-structures and dust composition. The majority of our objects are Class II Herbig AeBe and T Tauri disks. In my talk, I will present science highlights from the first five years of our survey, showing spectacular case studies. One such case is the disk of HD 144432 where VLTI's sub-au angular resolution allowed us to detect a three-ringed structure in the inner 5 au. The relatively short dynamical timescales in the inner disk enable us to track the motion of asymmetric dust features in 'real-time', using monitoring observations over a period of weeks to months. I will show how such observations reveal the orbital motion of clumps in the HD 163296 and in the DX Cha systems. Finally, I present the latest results on inner disk dust mineralogy from N band (8-13 micron) MATISSE observations.

recording: www.youtube.com/watch