Planetesimal formation in the inner region of the protoplanetary disk

Formation of the first gravitationally bound building blocks of planets, called planetesimals, is one of the most prominent challenges faced by our understanding of planet formation. As the dust growth is limited by fragmentation and radial drift, the direct growth to planetesimal sizes seems unlikely. However, the same processes drive the global redistribution of solids and may lead to a pile-up of pebbles that triggers planetesimal formation. I will present the recent models which combine dust growth, radial drift, and planetesimal formation via streaming instability. These results consistently show that the first planetesimals are more likely to be formed in the inner regions of the protoplanetary disk, where the dust growth timescale is shorter than the radial drift timescale