Around young stars across the galaxy, a cosmic clock has always been ticking — one that determines whether worlds like Jupiter will ever have the chance to exist. Using the James Webb Space Telescope, astronomers have now observed 72 infant solar systems to map how magnetic winds and stellar radiation systematically dismantle the gas reservoirs from which giant planets must be built, confirming long-held theoretical predictions with unprecedented clarity. The findings remind us that planetary systems are not inevitable — they are the product of a race between creation and dispersal, won or los