Stars form from the collapse of dense clouds, and as the collapsing gas and dust is rotating, a disk forms
around the star. Such disks are the birth places of planets and were referred to as ‘protoplanetary disks’.
However, the properties of disks during the onset of planet formation have been, and remain, a matter of
vigorous debate. We now know that disks have lifetimes of at most a few Myr rather than >10 Myr as previously
believed and observed ring structures strongly hint at an early onset of planet formation while the disk is still
embedded in its birth environment and fed by infall of gas and dust. Therefore, we are currently witnessing a
paradigm shift where even young disks are no longer considered as ‘protoplanetary’, but ‘planet-forming’
instead. While there is agreement today that external effects play a major role in the planet formation process,
relatively little work has been done so far in considering the protostellar environment.