In this episode, we journey to K2-18b, a "sub-Neptune" exoplanet that has become the center of a profound scientific debate. Orbiting a cool red dwarf star, this world sits in the elusive "Habitable Zone," but it is unlike anything in our own solar system. With a mass eight times that of Earth and an atmosphere rich in hydrogen, K2-18b might be a Hycean world—a planet covered entirely by a massive liquid ocean.
It challenges us to rethink what a "habitable" world looks like and reminds us that the first aliens we find might not be walking on land, but swimming in a global, alien sea.
