I think it has to be the Roswell, NM crash site in 1947.
Yes, many.
All UFO sightings are unexplainable, otherwise they wouldn't be unidentified.
They usually see UFO's at a UFO sighting
An alien report sighting can be reported to the local media or to NASA. Often times sightings can be found to be a fraud and will be put aside for more important tasks.
One of the most well documented UFO sightings occured in 2005 in Xapala, Mexico.
Probably the Roswell incident in the 40's.
Yes, I have witnessed 3 sightings in the Almeria region of Spain.
Roswell NM in 1947 seems to be the best documented and studied in modern history.
Yes.
James (Jimmy) Carter, who was the governor of Georgia at the time he reported the sighting.
On March 24, 2011, over Southhampton, England, a triangular, black UFO sighting in broad daylight.
The first actual UFO sighting was in 1500 B.C.!