(CNN) All around you, there are tiny particles suspended in the air, known as aerosols. That sort of picture is what you can see here in these composite images from NASA , representing the world as it was on August 23. The pretty clouds of blue, purple and red are representations of different kinds of aerosols in the atmosphere, gathered from NASA satellite data and measurements taken on the ground. "Some of the events that appear in the visualization were causing pretty serious problems on the ground," the NASA description reads. Most of the smoke over North America came from large wildfires burning in Canada and the United States."

Source: CNN August 25, 2018 14:03 UTC