Project Blue Book Case #1588. On July 24, 1952, an unidentified object was observed at Travis Air Force Base — the fourth Blue Book unknown from this Pacific transport hub (joining Cases #36 from 1947, #257 from 1948, and #1920 from August 1952). Four cases across five years made Travis one of the most persistent repeat-sighting bases in the database. The case was classified "Unknown."
