A new study challenges the dream of water-rich “Hycean” planets like K2-18b, suggesting that most sub-Neptunes lose their water deep into their interiors during formation. Instead of vast oceans, these worlds likely retain only a few percent of water at the surface.
A new study challenges the dream of water-rich “Hycean” planets like K2-18b, suggesting that most sub-Neptunes lose their water deep into their interiors during formation. Instead of vast oceans, these worlds likely retain only a few percent of water at the surface. A new study challenges the dream of water-rich “Hycean” planets like K2-18b, suggesting that most sub-Neptunes lose their water deep into their interiors during formation. Instead of vast oceans, these worlds likely retain only a few percent of water at the surface.