Interesting data and imagery from NASA around air pollution in China before, during, and after quarantines due to CoVid-19. The sensors look at NO2 levels that largely come from motor vehicles, power generation, and industrial facilities. The data is complicated a bit due to the Lunar New Year falling during the period, which normally results in drops in air pollution due to factory holidays. In addition, China adopted stricter environmental standards starting in 2020. But it would appear that much of the decline is due to the drastic quarantines that were a response to the Corona virus outbreak.