NASA — Even as Muscovites choked under a blanket of thick smoke in the first week of August 2010, concentrations of a colorless, odorless gas spiked to dangerous levels. A product of fire and a component of smoke, carbon monoxide is among the pollutants that wildfires spread across much of western Russia. This image, made with data from the Measurements of Pollution in the Troposphere (MOPITT) sensor flying on NASA’s Terra satellite, shows carbon monoxide over western Russia between August 1 and August 8, 2010. Read More