Happy Earth DayS

[From Apollo VIII, December 1968. Image via AP]

** ADVANCE FOR SUNDAY APRIL 22, 2007 AND THEREAFTER ** This Dec.1968 image released by NASA shows the Earth, and was taken during the Apollo VIII mission. Only two dozen men, those who traveled to the moon, have had the full Earth view. Most U.S. spaceflight has been in low orbit where only a piece of the Earth can be seen, a lesser but still impressive glimpse. (AP Photo/Courtesy of Earth Sciences and Image Analysis Laboratory, NASA Johnson Space Center)