On Earth, rain is made of water. On other worlds, it’s much worse. Take K2-141b, a lava planet where temperatures reach 3,000°C on the day side—hot enough to vaporize rock. This creates an atmosphere of molten rock vapor that condenses and rains down as actual stone. But it doesn’t stop there: violent winds carry this rock rain to the night side, where it refreezes into a solid crust. It’s a literal stone cycle, like Earth’s water cycle but with lava. Imagine needing an umbrella for molten rock.