The Roswell "UFO" Incident is arguably the most popular alien sightings of all time, and is celebrating its 66th anniversary today.

It was July 7,1947, about 75 miles from the town of Roswell, New Mexico, where a man named Mac Brazel found something unusual in his sheep pasture, according to History.com. There were metallic sticks held together with tape in the wreckage, and scraps of what was described as "heavy, glossy, paper-like material. "

Brazel reported his findings to the local sheriff, who then called officials at the nearby Roswell Army Air Force base. Soldiers cleaned up the mess, and whisked all evidence of the crash away in their armored vehicles.

On July 8, 1947, "RAAF Captures Flying Saucer on Ranch in Roswell Region" was the top story in the Roswell Daily Record, and has been the center of many conspiracy theories ever since.

According to History.com, Air Force officials claim debris was from a crashed weather balloon. Many believe it was an alien spacecraft that landed on Earth.

Another mystery attributed to the Roswell crash is the government project called Project Mogul. Since World War II, a group of researchers were working on a top-secret atomic espionage project.

"Project Mogul used sturdy high-altitude balloons to carry low-frequency sound sensors into the tropopause, a faraway part of the Earth's atmosphere that acts as a sound channel. In this part of the atmosphere, sound waves can travel for thousands of miles without interference, much like under the ocean," according to History.com. "The scientists believed that if they sent microphones into this sound channel, they would be able to eavesdrop on nuclear tests as far away as the Soviet Union."

The U.S. military claimed the items found in Brazel's field was from Project Mogul testings. However, there are many conflicting reports that also state the government believed the debris to be from a Russian spy plane.

Whatever the story may be, there are alien researchers who have dedicated their lives to debunking government claims, creating conspiracy theories and relentlessly searching for the truth behind the Roswell siting.

Checkout the video below for more insight into the Roswell incident.