Unknown flying objects (UFOs) have been reported around the globe throughout history, all the way back to 74 B.C. when Plutarch observed “the sky burst asunder, and a huge, flame-like body was seen to fall … In shape, it was most like a wine-jar, and in color, like molten silver."

UFOs truly captured the public’s imagination in 1938, when, with war looming in Europe, Orson Welles caused mass panic in America with his radio broadcast based on H.G. Wells' novel "The War of the Worlds," inspiring hysteria that space ships filled with aliens were invading Earth. World War II and the development of rocket science seemed to bring a new level of interest in sci-fi flying objects. And in 1947, when civilian pilot Kenneth Arnold reported seeing nine bright glowing objects flying in a "V" formation over Washington state's Mount Rainier, the public and media became officially obsessed.

Arnold measured the objects' flight speed at about 1700 mph and told reporters they looked like a saucer skipping on water, which is where the term “flying saucer” originated. In the wake of Arnold’s sighting, similar accounts were increasingly reported across the county, resulting in numerous photographs showing up in support of the sightings.

Although the following images were taken before the era of Photoshop facilitated such easy manipulation of photos, trickery and happy accidents (like faulty film, reflections or a dirty lens) could still account for what look to be UFOs — or could they be actual ships from space? Only the aliens know for sure.

1. Mount Washington, New Hampshire, 1870-1871

Possible image of UFO in the clouds above Mount Washington.Photo: Clough & Kimball, Concord, New Hampshire/Wikimedia Commons

This stereoscopic image is generally regarded as the first UFO photograph.

2. St. Paris, Ohio, 1932

George Sutton with an alleged UFO in the air behind himPhoto: Wikimedia Commons

A mid-day portrait of George Sutton, interrupted by a UFO photo bomb.

3. Tiensten, Hopeh province, China, 1942

Claimed UFO in Hopeh, China.Photo: Wikimedia Commons

Said to be taken by an American on duty in the region.

4. McMinnville, Ore., 1950

An alleged UFO in McMinnville, Oregon from a photo in LIFE magazinePhoto: Paul Trent/Wikimedia Commons

From a series of photos that were reprinted in LIFE magazine, perhaps the most famous of UFO images.

5. Salem, Mass., 1952

Possible UFOs over Salem, Mass.Photo: Wikimedia Commons

Taken by Coast Guard photographer Shell Alpert at a Coast Guard Air Station.

6. New Jersey, 1952

An alleged UFO over Passoria, New JerseyPhoto: George Stock/Wikimedia Commons

Here's a famous mysterious image from the Garden State made all the more mysterious since the CIA file lists the image as coming from "Passoria, N.J." — yet there's no "Passoria, N.J." on the map. (Cue theme from "The Twilight Zone.")

7. Trindade Island, 1958

UFOs over Trindade Island in 1958Photo: Almiro Baraúna/Wikimedia Commons

Taken by Almiro Baraúna aboard the Brazilian ship, Almirante Saldanha.

8. Santa Ana, Calif., 1965

A photo that shows a possible UFO over Santa AnaPhoto: Wikimedia Commons

One of four Polaroid photos taken by highway maintenance worker, Rex Heflin.

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