In February 1967, a family in the outskirts of Madrid, Spain, received a strange letter—written in a previously unseen language, accompanied by technical drawings and an alien symbol. The letter claimed to be from the planet “Ummo,” a civilization 14.6 light-years from Earth. This phenomenon, known as the Ummo Incident, lasted over 20 years, becoming the most complex alien communication event in UFO history.

📍 Location	📅 Date	🔍 Category
Madrid, Spain	1967-1990s	Alien Contact / Hoax

The content of the letters was extremely detailed, covering astronomy, physics, biology, and engineering. The Ummites (the Ummo aliens’ self-designation) claimed their spacecraft used a “magnetic gravity” propulsion system and provided detailed descriptions of robots, medical technology, and the structure of the universe.

The number of letters and documents grew continuously, exceeding thousands of pages by the late 1970s. The Ummites also claimed their spacecraft had landed in various remote areas around the world, including France, Spain, and the United States.

What makes the Ummo Incident so fascinating is that some of their “predictions” and technological descriptions later came true. For example, in the 1970s, they accurately predicted the emergence of CD-ROM laser storage technology and precisely described the principles of DNA repair technology. These “predictions” led many scientists and engineers to take the Ummo letters seriously.

The Ummo mystery peaked in the 1980s, when Spanish television and newspapers widely covered it. Some university professors even held lectures specifically discussing Ummo’s technical documents.

But then—in the early 1990s, the myth began to crumble. Spanish investigative journalist Javier Sierra and other researchers found that the technical details in the letters contained too many contradictions with known scientific facts. More critically, a figure who claimed to be the originator—rumored to be a Spanish engineer or scientist—stated that it was merely a social experiment.

The Ummo Incident was ultimately deemed one of the most elaborate UFO hoaxes in history. However, its cultural impact was profound—it increased public attention on UFO and alien topics while also reminding UFO researchers to be cautious about so-called “alien communications.”

📚 Sources

• Sierra, J. “Ummo: The Ultimate Alien Communication” (1994), EDAF
• Jiménez, J.M. “Cartas de Ummo: Una Investigación” (1988)
• Forteana Society, “The Ummo Mystery: 30 Years of Correspondence” (1997)