The city of Harbin, and much of northeastern China, experienced truly horrific air pollution earlier this week. There was so much smog, largely thanks to the burning of coal during the first cold days of the fall, that children were sent home from school, hospital admissions soared and highways were closed. Pictures from Harbin told the story—Chinese citizens, with surgical masks around their faces, disappearing in a white, ashy gloom. But you can’t really understand just how widespread China’s air pollution is until you see it from space. The above photo is from NASA Suomi-NPP satellite, captured on Oct. 21, shows eastern China cloaked in smog. And if China can’t cut down on coal combustion, it’s likely to get a lot worse.