Alien conspiracy theories suggest that extraterrestrial beings have visited Earth and that governments, particularly the U.S. government, are hiding evidence of these encounters. Proponents believe that incidents like the Roswell UFO incident in 1947 and sightings of unidentified flying objects (UFOs) are part of a larger cover-up. Many conspiracy theorists argue that advanced technology, such as Area 51, is used to study alien spacecraft and beings. These theories often include claims of secret agreements between humans and aliens, as well as the idea that aliens are influencing human affairs or even abducting people for research.