On the morning of September 10, 1990, at 8:30 AM, an irregularly-shaped object hovered for 50 minutes over construction land in São Vicente de Alfena, Valongo, near Porto, Portugal. Approximately 50 witnesses spread across a 2km² area observed the phenomenon. What makes this case exceptional, and largely unknown outside Portugal, is what happened next: the photographs were authenticated by NASA and Kodak.
The Sighting
Witnesses described the object with different geometries, "spherical with five appendages", "a turtle with legs", "a cement mixer", which is consistent with simultaneous observation of a three-dimensional complex object from different angles. The object descended to the level of a third-floor window of a building under construction before slowly ascending and disappearing.
Amateur photographer Manuel Moura, present at the scene, managed to take four photographs. These images became the central element of all subsequent investigation.
50 minutes of observation by approximately 50 independent witnesses across a defined geographic area eliminates any hypothesis of brief misidentification. The duration and number of witnesses make this the most robustly documented UAP sighting in Portuguese history.
NASA and Kodak Authentication
The four photographs were submitted for independent analysis to Richard Haines, a research consultant at NASA with expertise in aerial phenomenon image analysis, and to Kodak laboratories. Both entities certified the authenticity of the images, the photographs showed no evidence of manipulation using techniques available in 1990.
The Portuguese Institute of Meteorology and military entities confirmed that the object did not belong to their inventory of known aircraft or equipment. The Portuguese Air Force had no record of any aircraft in the area at the time.
NASA and Kodak authentication does not mean the object was of non-human origin. It means the images are genuine, the photographed object physically existed at the location and at the time of the sighting. This distinction is critical and frequently lost in media coverage of this case.
The CTEC Investigation
The Centro Transdisciplinar de Estudos da Consciência (CTEC) at Universidade Fernando Pessoa conducted the most extensive investigation of this case, including witness interviews, photographic analysis, and compilation of a formal report. The case is considered by CTEC to be the most significant documented UAP sighting in Portugal to date.
The case was covered by Jornal de Notícias the following day (September 11, 1990) and has since been referenced in international UAP research literature.
GIFO Analysis
The Alfena 1990 case represents the strongest evidentiary foundation in the Portuguese national archive precisely because of the combination of physical evidence (authenticated photographs), large-scale independent witness testimony, and institutional confirmation of the object's unknown origin from both meteorological and military sources.
GIFO recommends modern digital analysis of the original photographs using contemporary forensic image analysis techniques, which were not available in 1990.
Classification: Historical, Unresolved
Primary reference case for the national archive. The Alfena 1990 case is the most documented anomalous occurrence in Portuguese history. Photographs authenticated by independent entities of high credibility. No conventional explanation has been accepted. GIFO recommends modern digital reanalysis of original photographs. Sources: Jornal de Notícias (11 Sep 1990); CTEC, Universidade Fernando Pessoa; NiT (Aug 2021); Wikipedia PT. Ref. GIFO-REF-003 · Historical Archive 2026.