Earth Day is April 22. There is no shortage of famous musings on what Carl Sagan once called our 'pale blue dot.' Here are 10 of our favorite things said about planet Earth.
"Near the sun is the center of the universe. Moreover, since the sun remains stationary, whatever appears as a motion of the sun is really due rather to the motion of the earth."
– Nicolaus Copernicus, "De Revolutionibus Orbium Coelestium," 1543