Ship Tracks over the Pacific Ocean.

What are those unusual streaks? Some images of planet Earth show clear bright streaks that follow the paths of ships. Known as ship tracks , these low and narrow bands are caused by the ship's engine exhaust. Water vapor condenses around small bits of exhaust known as aerosols , which soon grow into floating water drops that efficiently reflect sunlight . Ship tracks were first discovered in 1965 in Earth images taken by NASA's TIROS satellites . Multiple ship tracks are visible across the featured image that was captured in 2009 over the Pacific Ocean by the MODIS instrument on NASA's Terra satellite. Inspired by ship-tracks, some scientists have suggested deploying a network of floating buoy s in the worlds' oceans that spray salt-aerosol containing sea-water into the air so that, with the help of the wind, streams of sunlight-reflecting clouds would also form. Why do this? These human-made clouds could reflect so much sunlight they might help fight global warming .

Today is: World Oceans Day