Panama.Panama Canal · U.S. military radars track unknown objects

In March 1958 the Panama Canal Zone was a territory under U.S. administration and the seat of the U.S. Caribbean Command, with Army, Air Force, Navy and Marine Corps bases. Air traffic was unusually heavy those days: aircraft were arriving early for the Armed Forces Day celebrations, among them F-100 Super Sabre fighters, H-19 helicopters and B-57 bombers. In that crowded sky, radars picked up two objects that matched no flight plan.

At 8:03 p.m. on March 9, the Army's anti-aircraft operations center at Fort Clayton received a radar alert about an unidentified aircraft approaching the Pacific side of the isthmus. While operators followed that first spot on the screen, two more appeared at 8:45 p.m. The first was a Chilean Airlines plane that landed at Tocumen airport; the other two stayed unidentified, near Fort Kobbe. A civilian aircraft in the area searched by eye and saw nothing. A search radar had picked them up first and handed them to the tracking radar of Battery D on Flamenco Island (Fort Amador), which followed them until 2:08 a.m. on March 10: two objects about 100 yards apart, on a steady, nearly circular path over Fort Kobbe, in clear skies with unlimited visibility and no wind. Their altitude varied between 2,000 and 10,000 feet.

The log of the Air Force's movement and identification section noted at 8:45 p.m. an "unidentified blip believed to be weather balloon" that appeared to be orbiting, and that a balloon had been released around 6:30 p.m. and should by then be down southeast of Albrook base. At 11:45 p.m. the object was at 3,500 feet and a searchlight was readied, to be run from a crash boat. At 11:55 p.m. it was at 6,000 feet and moving away very rapidly to the southwest. At midnight the radar advised that "as soon as searchlight was employed, the object became evasive," now at 10,000 feet. The Army report says that when the searchlight beam touched the objects, they traveled from 2,000 to 10,000 feet in five to ten seconds.

At 12:44 a.m. Braniff Flight 400, guided by radar to about 100 yards from the object, reported seeing nothing; it landed at 12:47. At 12:55 the radar showed two objects about 100 yards apart. Contact was lost at 2:10 a.m. according to the log; the Army report says 2:08. From the stations, personnel said they saw "red and green lights," with no noise and only for a short period, in good visibility. A second tracking radar, on Taboga Island, locked on the same return. Operators said the signal was strong and easily distinguished from cloud formations. Maintenance personnel checked the radar thoroughly during the observation, and when the lock broke, the equipment picked the object up again at once. Its movement was very erratic and at times looked evasive.

At 10:12 a.m. on March 10, the search radar logged an unknown return west of the canal. The log says it reached "900K" (900 knots) and then stopped completely "for several minutes" before moving again. The Taboga tracking radar calculated, as the object moved away from two jets, a speed of about one thousand miles per hour. A T-33 jet took off from Howard Field to investigate; according to the record, each time it closed in, the object "would move several miles away, then stop." The aircraft reached the immediate area of the return and saw nothing. Contact was lost at 2:15 p.m.

Capt. Vernon D. Adams of the Air Force summarized the episode in an official report: the Canal Zone radars tracked several unidentified targets on March 9 and 10, and two of them were investigated by aircraft, with negative results. The case entered Project Blue Book, the Air Force program that between 1952 and 1969 investigated more than 12,000 reports, of which 701 remain unexplained, as case IR-4-58.

Blue Book considered it explained. The analysis by its technical intelligence office, signed by Col. Gordon C. Hoffman, attributed the first sighting, on the night of the 9th to the 10th, to "one or more balloons," since the targets were "more or less stationary except for altitude changes": the tracking radar could have lost a balloon at low altitude and locked onto another higher up, which would give the impression of a rapid climb. It rated a false radar echo "a very small possibility," because a second radar locked onto the same object. The second sighting, in daylight on March 10, it attributed to a false radar echo because of the erratic signal. The case card closed it as "probably balloon" and "false target" (a radar signal that corresponds to no real object).

The same file holds evidence against that reading. The Army report says the balloon possibility was discarded when the Air Force stated no balloons were in the air at that time. The Air Force report says the returns were strong and easily distinguished from clouds. And while the Army report says the searchlight beam "touched" the objects, the Blue Book analysis says "efforts to sight the target visually failed."

Several military instruments followed the same objects for hours: a search radar, two tracking radars (Flamenco Island and Taboga) and, according to the Army, an anti-aircraft searchlight. What the record attributes to the objects, a climb from 2,000 to 10,000 feet in seconds when lit up and a return that moved away from the T-33 each time it closed in, is what made the case circulate as unexplained.

No pilot saw anything. Neither the airliner about 100 yards from the object on the night of the 9th, under clear skies with unlimited visibility, nor the T-33 in the immediate area of the return on the 10th. A balloon accounts for nearly stationary objects that the searchlight never managed to show, and the radar jumping from a low balloon to a higher one accounts for the apparent climb. The evidence against it, that the Air Force said no balloons were in the air and that the signals were easily told apart from clouds, stays unresolved in the file.

The event took place over the Canal Zone, then under U.S. administration and not under Panamanian jurisdiction.