Scanning Electron Microscope Still Image of Pollen Particles

Aerosols are complex particles that come from a variety of sources. They occur in nature, but can also be generated by human activity. Pollen grains are an example of short-lived aerosols that are difficult to detect but are found near the Earth's surface. Pollen effect human health, but researchers do not consider these aerosols to be part of the climatologically important population of tropospheric aerosols. This Scanning Electron Microscopic image reveals pollen grains from a variety of common plants: sunflower (Helianthus annuus), morning glory (Ipomoea purpurea ), prairie hollyhock (Sidalcea malviflora), oriental lily (Lilium auratum ), evening primrose (Oenothera fruticosa), and castor bean (Ricinus communis).

See http://glory.gsfc.nasa.gov