Comic books have happily subscribed to the theory of multiple universes for decades. After all, how else could flying and leaping versions of Superman exist at the same time? In the real world, things are a little different.
Human beings have only gone as far as the moon and back -- and that's certainly an accomplishment in and of itself. But what other methods do scientists use to learn about our galaxy and beyond? What have we achieved so far in our exploration of the final frontier?
NASA has an SUV-sized rover on Mars, and it’s sending new data back to Earth all the time. Landing Curiosity (and other rovers) on the red planet is no small affair. Check out these pictures of rovers and the extreme engineering that goes into a successful mission.
The Voyager space probes took dazzling pictures of planets no one had ever seen. And they're still on the move, carrying golden records with a message for aliens -- complete with bagpipes and Louis Armstrong.
Because an Earth-like environment is created within a spacesuit, it allows you to walk around in space in relative safety. But outer space is an extremely hostile place and could kill you if you aren't protected.