                        Astronomy Picture of the Day

    Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                                 2022 June 8

                     Ship Tracks over the Pacific Ocean
         Image Credit: NASA, Terra, MODIS; Text: Raymond Shaw (MTU)

   Explanation: 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 buoys 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
                       Tomorrow's picture: open space
     __________________________________________________________________

       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
                NASA Web Privacy Policy and Important Notices
                      A service of: ASD at NASA / GSFC
                             & Michigan Tech. U.

