No one knows where it went.
Left behind, more than a half-century after the alleged extra-terrestrial touch-down, is a friendly divide between those who believe and those who don't — those who call the event legend and those who call it truth.
Regardless of their stance, many will convene this week at the 14th annual Aztec UFO Symposium, this year themed "The Truth is Out There."
The town's lingering curiosity and enthusiasm about UFOs has made the symposium a constant success. It is one of the library's most successful fundraisers, bringing in several thousand dollars for literacy programs at the Aztec Public Library, event planner Katee McClure said.
This year's most foreign attendee is traveling from Illinois, though others have traveled from Canada and Hawaii in the past. Slightly fewer than 300 visitors are expected this year.
"People have heard everything they can about Roswell. They heard everything about Kingman, Ariz. They want to hear about modern-day evidence," McClure said.
Featured speakers include an author who will lay out evidence that the human race was an alien genetic engineering project from 250 million years ago, a researcher who's collected debris and evidence of UFO crashes all around New Mexico and an abductee from England who says he's experience 50 years of contact with extraterrestrials.
As for information on Aztec's history, those who attend the symposium will have the chance to tour the 1948 crash site, where townspeople say they found an intact UFO.
However, the one man who seems to know all the answers about the site won't be able to attend this year. He's busy writing a book that will tell the whole story.
"I think if you took a poll of the Four Corners population, you'd probably have a major chunk say it never happened," said Scott Ramsey, who is writing the last chapter of a book titled "Aztec Incident."
Ramsey, who moved from Farmington to North Carolina years ago, is in his 23rd year of research.
"One guy e-mailed me saying, 23 years and you don't even have a lug nut off that thing,'" Ramsey said, referring to his lack of physical evidence.
In all of that research, which is solely on Aztec's encounter with celestial visitors, Ramsey has collected hundreds of thousands of documents, he said.
"Boxes and boxes and boxes and boxes full," he said.
The "Aztec Incident" begins on March 25, 1948. A pair of oil workers, 19-year-old Doug Noland and fellow employee Bill Ferguson, were starting a normal day of work.
However, when called to a brush fire on the top of a mesa just south of Aztec, the pair found something very abnormal.
Noland described the discovery as a "very large metallic lens-shaped craft," Ramsey said. There were no seams to the metal, which looked to be brushed with aluminum. Quarter-sized portals reflected back and gold rings circled the outer shell.
What waited inside was even more perplexing, Ramsey said.
"As Doug and Bill looked through the window, they saw two small bodies slumped over what appeared to be a control panel of sorts,'" Ramsey wrote in his book. "Doug remembered, The sun was coming up by this time, but we could plainly see two bodies.'"
Ramsey provides countless other testimonies from witnesses, ranging from Baptist ministers to neighboring ranchers.
Still, Ramsey cannot answer where the craft was taken.
Those who saw the craft said it disappeared shortly after mysterious law enforcement officials arrived.
Bystanders speculated that the officials were from the military base in Los Alamos, a base known for its covert operations and testing.
"They told me this event was extremely important to the United States of America — that we were responsible for our national security, and that we will never talk to anyone about this event," Noland told Ramsey. "They weren't kidding around."
The officials were "very serious and not very friendly," Noland told Ramsey. "We were threatened with our lives if we ever spoke about this. ... We did not see anything, according to them. Nothing was there. We weren't there."
The mystery of what happened may remain unsolved forever. However, the story thrives as one of Aztec's most cherished tales, whether truth or legend.