This "Earthrise" photo from the Apollo 8 mission has long been one of my favorites, and it is especially appropriate today:
Happy Earth Day to you all!
update (4/24 @ 10:15am):
Here's a belated Quote of the Day, from Apollo 15 astronaut James Irwin:
"The Earth reminded us of a Christmas tree ornament hanging in the blackness of space. As we got further and further away, it diminished in size. Finally it shrank to the size of a marble, the most beautiful you can imagine. That beautiful, warm, living object looked so fragile, so delicate, that if you touched it with a finger it would crumble and fall apart. Seeing this has to change a man."
I hope that everyone who sees that photo is indeed changed, if only just a little bit, for the better...