Ubatuba

Ubatuba and the Magnesium Fragments

In September 1957 a Brazilian newspaper received a letter from a fisherman claiming that a disc-shaped object had exploded in the air over the beach at this town in front of him, enclosing several light metal fragments. The samples reached a Brazilian agricultural laboratory, which identified almost pure magnesium. The argument starts there: some analyses showed a purity above what industry could achieve at the time, others found it ordinary. The fragments were passed from hand to hand and laboratory to laboratory, some were lost, and some were studied in the United States in the 1980s. Sixty years on the result is inconclusive, and the Ubatuba fragments remain the best-known example of how physical evidence in this subject dissolves along a chain of custody.