Bonilla Observation — First Photographed UAP

On August 12–13, 1883, José Bonilla, a professional astronomer at the Zacatecas Observatory in Mexico, made a series of photographic observations that are now recognized as the earliest known photographs of unidentified flying objects. While conducting routine solar observation using a wet collodion photographic process, Bonilla noticed hundreds of dark objects crossing the solar disc and, having the presence of mind to photograph them, documented 447 separate objects transiting over a two-day period.

Bonilla's photographs showed the objects as dark, irregular ellipsoidal forms silhouetted against the bright solar disc. They moved in groups and individually, with consistent trajectories suggesting controlled or at least organized movement rather than random debris. He estimated their altitude as relatively low based on the parallax shift when he compared observations from different positions — meaning the objects were within Earth's atmosphere or very close to it, not distant space objects. He telegraphed the Mexico City Observatory asking whether they were seeing the same objects; they were not, suggesting a highly localized phenomenon.

Bonilla published his observations and photographs in the French astronomical journal L'Astronomie in 1886, making this one of the few 19th-century UAP cases to enter the peer-reviewed scientific literature. His account was treated cautiously by the astronomical community, with various explanations proposed including migrating birds, insects near the lens, and atmospheric particulates — none of which adequately explained 447 individually photographed objects with distinct trajectories crossing the solar disc over two days.

In 2011, astronomers Hector Manterola, María de la Paz Ramos Lara, and Guadalupe Cordero published an analysis in the Monthly Notices of the Royal Astronomical Society arguing that Bonilla's objects might have been fragments of a disintegrating comet passing very close to Earth — possibly within 8,000 kilometers. If correct, this would represent one of the closest known cometary approaches in recorded history, and the event's non-observation at other observatories would be explained by the extreme parallax at such proximity.

Whether cometary or genuinely unidentified, the Bonilla photographs represent the first documented scientific observation and photography of mass unidentified aerial objects, giving the case a unique historical position at the intersection of astronomy and UAP research.