Star Trek: 10 Times Aliens Influenced Human History
3. The Roswell Incident
The Roswell Incident is probably the most famous real-life UFO controversy in American history. In 1947, a substantial amount of debris was found in Roswell, New Mexico, and it didn't take long for the public to go wild with claims that the debris came from a crashed alien spacecraft.
The debris was ordered to be taken to Fort Worth Army Air Field as soon as the military became aware of it, which only furthered conspiracy theories of a government cover-up, but the American government maintains to this day that the debris actually came from a nuclear test surveillance balloon from Project Mogul, a top-secret project (which explains the secrecy of the cleanup).
In the Deep Space Nine episode Little Green Men, we learned that the debris actually did come from outer space. Specifically, a crashed Ferengi shuttle containing Quark, Nog, Rom, and Odo, who were accidentally sent to Earth's past. They were sent to a heavily-guarded military base and interrogated before escaping and returning to the future with the help of some compassionate Humans who didn't want them to be experimented on.
These events were covered up by the military, but that didn't stop Odo and the three Ferengi from accidentally starting one of the biggest UFO conspiracy theories ever.