Protoplanetary Disks Gas Giants Water Vapor Terrestrial Planets Brown Dwarfs Rocky Planets Simulation Disk Instability Accretion Theory Core Accretion Metal Content Models Cold Jupiter Primordial Nebula Exoplanets Research Models Observational Evidence Cosmic Dust Stellar Characteristics Planetary Migration Protoplanetary Discs Stellar Evolution Migration Processes Migration Mechanisms Exoplanet Dynamics Planet-Forming Disk Planet-Forming Disks Theories Shape of Young Planets Shape of Planets Disc Instability Supercomputer Simulations Observations of Young Planets Disc Fragmentation Disc-Instability Theory Protoplanet Shape Gas Giant Planets Observations Water Vapour Protoplanetary Disk Baby Planets Water Influence Chemical Composition Planetary Systems Disc Observation Planet Composition Research Tools Disk Winds Disk Evolution Disk Dispersal Mechanisms Young Stars Planet-Forming Discs Challenges in Explanation Star-Forming Regions Low-Density Planets Radial Velocity Measurements Rogue Planets Giant Stars Disk Chemistry Asteroid Collision Dust Grains Sulfur Influence Sulfur