Satellite data map of the average nitrogen dioxide (NO2) levels in China between February 10th and 25th 2020, during the 2019-20 Covid-19 outbreak. Nitrogen dioxide is a pollutant gas produced during industrial fossil fuel combustion and by road traffic. Quarantines to stop the spread of the new coronavirus, SARS-Cov-2, that is the cause of Covid-19 have lead to a reduction in NO2 emissions from both industry and traffic. Data obtained by the Tropospheric Monitoring Instrument (TROPOMI) on ESA?檚 Sentinel-5 satellite. See C048/8941 for average NO2 levels in January 2020.