We have named this world for beauty and sung to it for millennia, watching it linger near the horizon as the brightest object in our sky after the Moon. Yet the gentle light that reaches us from Venus travels from a place where lead melts on the ground and the very air has become a supercritical fluid. This episode follows an imaginary descent through the layers of the Venusian atmosphere, moving from the profound cold of its upper reaches down through sulfuric acid clouds and hurricane-force winds to a surface crushed under ninety-two bars of pressure.

The journey explores the sequence of events that unfolded over hundreds of millions of years to create this extreme environment. Venus may once have resembled Earth far more closely, possessing oceans that could have dissolved atmospheric carbon dioxide and locked it away in rock. But a shif ...