Transcript:

Apollo 11 the Scale of the Universe Orbiting the moon, looking back on Planet Earth, 239,000 miles away, gives you a hint of the scale of the universe. I'm Jim Metzner and this is the Pulse of the Planet. Michael Collins onboard Apollo 11:Seeing earth as we see it, out our left hand window. A little more than a half earth. We're looking at the eastern Pacific Ocean.. Michael Collins was the command module pilot on Apollo 11. Fifty years ago, he circled the moon, while Buzz Aldren and Neil Armstrong walked on it. Collins: You read in astronomy books that going from the earth to the moon is really like going from one grain of sand to the adjoining grain of sand on a vast beach. That is certainly true. But it seems farther than that when you're out at the lunar distance, which is only a quarter of a million miles away. It does seem very, very far, yet at the same time that isn't very far at all in cosmic terms. The nearest star for example, is Alpha Centauri and it's over four years away, if one could travel at the speed of light, which we're not able to do. And yet Alpha Centauri itself is just in one little obscure corner of one tiny little galaxy, pushed over at the side of the universe. So, you come to realize that that first grain of sand may only be right next to you on that beach, but the beach is so large that you simply cannot conceive of the ends of the universe. With thanks to astronaut Michael Collins, I'm Jim Metzner and this is the Pulse of the Planet.