One of Bonilla's photographs.
On August 12, 1883, the astronomer José Bonilla reported that he saw more than 300 dark, unidentified objects crossing before the sun while observing sunspot activity at Zacatecas Observatory in Mexico. He was able to take several photographs, exposing wet plates at 1/100 second. Although it was subsequently determined that the objects were actually high flying geese, Bonilla is usually given the distinction of having taken the earliest photo of an unidentified flying object, with some ufological literature interpreting the objects as either alien spacecraft or an unsolved mystery.
New research conducted by National Autonomous University of Mexico suggest that the unidentified objects may have been fragments of a billion-ton comet. 
External links