霧氣

雾 = 务 + 雨 : Willy Walrus (wu) has a special task (务) to fulfill in the space station's bathroom (Ø4). With a vaporizer he is creating a lot of fog (雾) which will slowly form a cloud and result in rain (雨). Willy will collect the rain and vaporize it again. With this experiment he is doing an important contribution in understanding the world's climate system.

Mnemonic symbol: a balloon. The Queen of Hearts is disappointed by her balloons. She expected them to float upwards, but in the space station's bathroom, They float randomly in all directions.