Satellite data map of the nitrogen dioxide (NO2) levels in the northeastern USA for March 2020, during the 2019-20 Covid-19 outbreak. Nitrogen dioxide is a pollutant gas produced during industrial fossil fuel combustion and by road traffic. The shelter-in-place orders 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 Ozone Monitoring Instrument (OMI) on NASA's Aura satellite. See C048/7123 for average NO2 levels in March between 2015-19.