For much of the year, an efflorescent salt crust makes Lake Lefroy stand out as a bright, white spot in satellite images. But after heavy rains, the ephemeral lake in Western Australia takes on a different look. Large volumes of water do not persist for long in Lake Lefroy because the region’s hot, dry climate encourages evaporation. While water pooled in early February in a pattern that resembles a tropical fish, it’s unlikely the pattern will last. Lake Lefroy is frequently reshaped by changes in the prevailing winds that transport water back and forth between different parts of the playa.