Satellites, balloon-borne instruments and ground-based devices make 30 million observations of the atmosphere each day. Yet these measurements still give an incomplete picture of the complex interactions within Earth’s atmosphere. Enter climate models. Through mathematical experiments, modelers can move Earth forward or backward in time to create a dynamic portrait of the planet. NASA Goddard’s Global Modeling and Assimilation Office recently ran a simulation of the atmosphere that captured how winds whip aerosols around the world. Such simulations allow scientists to better understand how these tiny particulates travel in the atmosphere and influence weather and climate. In this visualization, covering August 2006 to April 2007, watch as dust and sea salt swirl inside cyclones, carbon bursts from fires, sulfate streams from volcanoes—and see how these aerosols paint the modeled world.