The Aura spacecraft orbiting 400 km above the Earth (248 miles) has the capability to sense many different kinds of particles (physical and chemical) in the air. The Ozone Monitoring Instrument (OMI) aboard the Aura spacecraft picked up smoke from the recent fires in California. You can visit the Aura website to see an animation of how the smoke traveled during the recent activity:
http://aura.gsfc.nasa.gov/science/feature-103107.html
