Description: While only two years old, World Migratory Bird Day is just one of the latest evolutions in conservation awareness. Related celebrations go back more than twenty-six years and draw on over a century of research.
Description: The postcards in this gallery are from observatories associated with the Smithsonian. The Smithsonian Astrophysical Observatory established in 1890 in Cambridge, Massachusetts, is one of the Smithsonian’s research centers. Together with the Harvard College Observatory, it forms the Harvard-Smithsonian Center for Astrophysics.The Mt. Wilson Observatory opened in the early