(NewsNation) — A military veteran has come forward alleging a secret government program exists to recover craft from non-human species, and the House Oversight Committee has announced a plan to hold hearings on the issue of UFOs. But just how far back do stories of strange lights in the sky go?

America in particular has a unique fascination with sightings of strange objects in the sky, and most modern UFO lore goes back to the days of World War II. It’s a long history of mysterious lights and unexplained phenomena that have influenced pop culture and led to conspiracies about government coverups and secret research.

Here’s a timeline of some notable moments in UFO history that shaped America’s perception of what extra-terrestrial contact might look like:

Foo Fighters, c. 1940

Foo Fighters was the term WWII pilots gave to unexplained lights they spotted following their aircraft at night. Members of the 415th Night Fighter Squadron reported the unexplained lights to command, but an Associated Press story let the broader public know about the mysterious sightings.

The 415th wasn’t the only squadron to report sightings, either. Other pilots reported similar incidents. The Army investigated the incident, but the results were lost. Possible explanations have ranged from battle fatigue-induced hallucinations and secret German weaponry to natural phenomena like St. Elmo’s Fire.

The CIA also investigated the incident in the 1950s, but never offered a formal explanation for what the pilots had witnessed.

Kenneth Arnold sighting, 1947

The Kenneth Arnold sighting is considered the incident that kicked off America’s UFO craze. In the summer of 1947, Arnold was flying his small plane near Mount Ranier in Washington when spotted a series of bright lights moving in formation.

Arnold mentioned the incident to others when he landed and the story took off, and he described the unidentified objects as “flying saucers,” a term that would stick, even though he later claimed he was misquoted.

Still, the incident led to a wave of UFO sightings as well as a surge of science fiction featuring unexplained objects in the sky and extra-terrestrials that would continue to populate pop culture for decades.

Roswell, New Mexico, 1947

Probably the most well-known UFO sighting of all time, the Roswell, New Mexico incident continues to be the center of alien-related conspiracy theories. In the summer of 1947, W.W. “Mac” Brazel, a rancher, found strange debris on his property.

After hearing reports of the Arnold sighting, Brazel took the material to officials, who called in the military. The official explanation for the crash was a weather balloon and stories about bodies being recovered were actually anthropomorphic test dummies. However, many continue to believe it was something else that crashed to the ground.

The Roswell incident also gave rise to rumors about Area 51, a military test facility located near Groom Lake, Nevada. The base continues to be the center of conspiracies about recovered UFO material.

McMinnville UFO Photos, 1950

Oregon farmer Paul Trent took photos of a strange object in the sky. His wife spotted an object flying near their house that she described as silent and having no motor. She called her husband to see and he took the pictures, which are still considered to be the best photos of a purported UFO.

An Air Force committee investigated the sighting in the 1960s and found no concrete evidence the photos were faked. Regardless of whether the images are real, the images are iconic and have informed popular depictions of UFOs.

Washington, D.C. UFO Incident, 1952

Aircraft controllers in the nation’s capital reported multiple unexplained objects on radar near Andrews Air Force Base, which then spread out to the skies over the White House and the Capitol building. A week later, more strange lights were seen. When Air Force jets were scrambled to respond, the lights reportedly vanished as they got close only to reappear when the jets backed off.

The sightings were investigated by the Air Force’s Project Blue Book, which was tasked with looking into reports of UFOs. The project ran from 1947 to 1969, when it was discontinued.

Kelly-Hopkinsville Incident, 1955

In 1955, in the small town of Kelly, Kentucky, two men reported seeing an object land in a field, followed by the appearance of strange-looking, green beings. The men and other family members reported shooting at the supposed aliens with no results.

Authorities who investigated never found any evidence to support the claim and neighbors insisted they made up the story. However, it still made a big mark on America’s culture, cementing the idea of aliens as little green men and reportedly inspiring Steven Spielberg to make “E.T.”

Betty and Barney Hill Abduction 1961

Betty and Barney Hill were driving from their honeymoon in Canada late at night. The Hills, an interracial couple, did not want to stop despite the late hour over fears for their safety. While driving, they reportedly saw a strange object in the sky. The Hills reported seeing a bright light and then finding themselves in their car with two hours missing. Betty’s dress was torn and Barney’s shoe damaged, though neither could tell how that happened.

Under hypnosis, the couple reportedly recalled being taken into a ship by non-human beings who conducted medical exams on them.

While many doubted the Hills’ story and offered alternative explanations, including the possibility of false memories created during hypnosis, the incident still provided a template for abduction stories over the years.

Jimmy Carter UFO Incident, 1969

Former President Jimmy Carter is probably the most well-known figure to publicly report a UFO sighting. The incident happened in 1969 in Leary, Georgia where he and other members of a local Lions Club saw a silent ball of light in the sky, but Carter didn’t file a report on the sighting until 1973.

Before his presidency, Carter vowed that he would make all information on UFO sightings available to the public, but when asked later, said he couldn’t respond to questions on whether he pursued the UFO question while in office. Still, the former president has said he doesn’t believe the government is hiding anything.

USS Nimitz UFO Incident, 2004

Former Navy pilot Alex Dietrich was on a training mission with the USS Nimitz in 2004 when she and her commanding officer observed an object they described as a large Tic-Tac flying along the water. Dietrich has said she has no idea what the object was and said it behaved strangely. Dietrich also noted there were no visible means of flight control or propulsion that could be seen.

The sighting was notable because the Navy confirmed video of the footage was authentic, though it did not say the object was extraterrestrial.