  The discovery of thousands of exoplanets has shown that the birth of planets
is a very efficient process in nature. Several physical mechanisms have been
proposed to describe the assembly of planets in disks surrounding young stars.
However, observational constraints have been sparse on account of insufficient
sensitivity and resolution, especially for imaging the inner $10 - 20$ au from
the star, where most of planets are observed. Thanks to its unprecedented
angular resolution and sensitivity at wavelengths where the emission from the
circumstellar material is optically thin, the ngVLA has the potential to
transform our understanding of planet formation. In this chapter, we present
state-of-the-art theoretical models of planetary systems in the act of forming
that demonstrate ngVLA capabilities of imaging and follow the temporal
evolution of young solar system analogues up to the distance of the Orion
Nebula. These images will unveil how planets form and interact with their
parental disks, and will shed light on the diverse properties of exoplanetary
systems.
