Some people believe we have already come into contact with extraterrestrial beings. Whether the beings have actually landed here on earth is another question. Some people believe UFOs are alien spacecraft, while others believe there is evidence being kept hidden in Area 51 in New Mexico. It is also possible that we have had contact with other life forms through radio waves or some kind of satellite communication.
I believe there are other life forms out there and they have likely been around a lot longer than humans so are probably much more technologically advanced. Once we have the technology to detect the communication, I believe we will see that it was there all along.