UFO sightings are very interesting phenomena. Though a good number of them have been debunked and explained by analysts, there are still a number of incidents that, until now, still mystified investigators. Here are three of the world's most prominent encounters with UFOs.

The Phoenix Lights

Happening in 1997, the Phoenix Lights incident is arguably the largest mass UFO sighting in history, as a huge aircraft, which seems to be almost a mile wide from tip to tip, was seen by thousands of people in the area. While the incident was quickly covered up by the government as a military exercise, most of the people who witnessed the event remain convinced that what they saw on that fateful night was something from out of this world.

The Valentich Disappearance

Arguably one of the most hair-raising UFO sightings ever recorded involved a pilot-in-training, Frederick Valentich, who was flying in a Cessna 182 along the coast of Bass Strait when he reported seeing an Unidentified Flying Object in the area. He immediately reported the incident to air traffic controllers, ultimately talking about the mysterious object for minutes before the UFO, together with the young pilot, disappeared without a trace.

The Roswell Incident

The 1947 alleged UFO crash in a field in Roswell, New Mexico, is arguably the most iconic UFO-related incident of all time. Indeed, the number of people involved, as well as the sheer number of accounts pertaining to the event, all but prove that something quite extraordinary crashed in the state that year. With the U.S. military getting involved and the government persuading people that the crash was just a weather balloon, it is, nonetheless, an incident to remember.

Eventually, UFOs might be debunked by science. Indeed, with researchers studying them nonstop, there is a pretty good chance that the truth about these incidents, would finally see the light of day.