These tracks were made south of Alaska when water vapor condensed on particles in ships' exhausts. -- Click on the image for the same scene in false color, showing the relative size of the particles: yellow-orange indicates small particles; lavender-purple, large ones. -- To find out how the particle size affects the intensity of the scattered sunlight, visit Ship Tracks South of Alaska. -- To learn about the effects of aircraft contrails on Earth's climate, see this Physics in Your World.
