"Frequently on the lunar surface I said to myself, 'This is the Moon, that is the Earth. I'm really here, I'm really here.'"
This quote from Alan Bean, Apollo 12, is from an interview he did soon after he returned from the Moon. I really love this one because I have the feeling that this would be my reaction - like, "I so want to be here in this moment, but I can't quite wrap my brain around what is going on. Is this really happening?"
I have many times walked out of the lab and seen the Moon hanging in the sky and thought about how the bits of rock and dust that I was just looking at come from up there, and even that thought sometimes seems inconceivable, but to be up there looking at the Earth in the distance must be mindboggling, utterly and completely mindboggling.
Alan Bean, by the way became an amazing artist after his astronaut career ended. Here is a lovely painting he did of the view looking back at "Mother Earth" and another he calls "A jewel in the heavens". You can find more of his work at www.alanbean.com.
Countdown to Earth Day part 1 part 2 part 3 part 4 part 5