ImmortalJ is spot on!
I like to think of the universe or space as a gigantic ocean. Our little earth is just a mere island in space, and all those other galaxies and planets are islands in our endless ocean. Imagine if you were one of the first members of the human race who was born on one of the thousands of islands that make up Singapore. You may be able to see other islands from your island but until the invention of boats and ships you can only dream of what those islands would be like. Space and the universe is just like that but on a higher level. Our Earth is one of those tiny islands and now that NASA is planning to build a moon base, you could say we're taking our first steps towards space travel. We live in exciting times. I wonder what Galileo would think if he were alive today. Stoned astronomy with him would be awesome. Ok, now I'm rambling...