Two recently taken photos document the power of water. One of them records destruction, the other reveals growth. In one, we see Hurricane Harvey bringing torrential rain and flooding to Houston, the fourth-largest American city, and causing damage that will cost millions of dollars to repair. In the other, we see the Atacama Desert, one of the most arid landscapes on earth, where decades can pass without a single drop of rain. Suddenly it has come to life with a carpet of purple wildflowers reaching to the foot of the Andes, now that rain has fallen on its stones, sand, and scree.