JWST has revealed that young planetary systems lose their planet-building gas through a changing mix of powerful jets, molecular winds, and radiation-driven outflows. As the disks age and their gas disappears, giant planets face a shrinking window to build massive atmospheres.

JWST has revealed that young planetary systems lose their planet-building gas through a changing mix of powerful jets, molecular winds, and radiation-driven outflows. As the disks age and their gas disappears, giant planets face a shrinking window to build massive atmospheres.