Nowadays, it's almost like we take space travel for granted. Spectacular pictures come back from telescopes and space probes, and we give them a glance, maybe say "wow," and then move on to the latest news about the iPhone 5 or whatever.
Over the last half century, though, our knowledge about our universe (and particularly our solar system) has increased exponentially, thanks to the development of spacecraft capable of making it to other planets and then sending back pictures when they get there. It hasn't been easy, but as milestone after milestone has been reached, our perception of our place in the cosmos has expanded.
In the gallery below, experience some of the firsts of our species' various space programs around the world, from the first picture ever taken from orbit to the first image of our entire solar system all at once. Think back a few decades, before we had Hubble and Cassini and Mars Global Surveyor, and let your mind be blown by what our space program has accomplished.