NASA Image: Ship Tracks
On March 4, 2009, the skies over the northeast Pacific Ocean were streaked with clouds that form around the particles in ship exhaust. This pair of images shows how these ship tracks are different from the natural marine clouds in the same area.
NASA images by Robert Simmon and Jesse Allen, based on an image by Jeff Schmaltz, MODIS Rapid Response Team. Caption by Rebecca Lindsey.
(Source: Earth Observatory)