From seeing streaks of light across the sky to floating orbes in the backyard, people across the USA have reported unidentified objects over the years.
The National UFO Reporting Center has a State Report Index that breaks down UFO sightings by state, duration of sighting, shape and description.
Here are the 10 states with the most UFO sightings, according to the center:
1. California: 11,092
2. Florida: 5,017
3. Washington: 4,951
4. Texas: 4,313
5. New York: 3,799
6. Illinois: 3,031
7. Arizona: 3,143
8. Ohio: 2,883
9. Michigan: 2,424
10. North Carolina: 2,247
Sightings in the database range from the 1950s to 2015.
In the past week, almost 136,000 pages of declassified UFO records, known as Project Blue Book or the Air Force's files on UFO sightings and investigations, were put online.
Project Blue Book was based at Wright-Patterson Air Force Base near Dayton, Ohio. The project investigated sightings of strange phenomena from 1947 to 1969. While many of the sightings were attributed to air traffic or Mother Nature, 701 remain "unidentified."
"Project Blue Book is the last time the federal government claimed they studied UFOs but we suspect they never stopped," says Roger Marsh, spokesman for Mutual UFO network.
Marsh says 90% of the sightings their organization receives can be explained, but 5-10% of the cases are unresolved.
Other Stories 2 Click On: