Rain is not the same everywhere in the universe. On Earth, clouds produce familiar water rain that falls onto oceans and land. Deep inside Neptune, scientists believe extreme pressure and temperature may cause carbon to form diamond crystals that sink downward, creating what is often called “diamond rain.” Meanwhile, the ultra-hot exoplanet WASP-76b has an atmosphere hot enough to vaporize iron. Powerful winds can carry iron vapor toward the cooler side, where it may condense and fall as metallic rain. These three worlds show how different planetary environments can create completely different forms of precipitation. From ordinary water to diamonds and molten metal, the universe is far more extreme than Earth.
