Many people would like to believe that there is life on some of the other planets or somewhere else in the universe. Movies, TV shows, and lots of books have been produced to show how different life on Earth might be after a visit from a few aliens in UFOs. People on Earth listen for signals, send messages on space probes, and try to develop quicker ways to travel in space. If there is intelligent life out there, they hope that some day, some way, they can go visit them.