History Mystery from the Archives

By Susan Thompson, CECOM Command HistorianSeptember 24, 2019

Weather balloon .... or infamous Jersey UFO?
(Photo Credit: U.S. Army) VIEW ORIGINAL

Did you know there was a UFO sighting at Fort Monmouth, New Jersey, which played a major role in re-invigorating the official Air Force investigation on UFOs?

On the morning of September 10, 1951, a radar demonstration was being conducted for a number of Army dignitaries, when the radar technician who was operating the equipment picked up an unknown low-flying target moving faster than the automatic setting mode on his AN/MPG-1 radar set could plot. This would mean that it was flying more the 700 miles per hour, which was right at the upper capability of jets at the time.

About 15 minutes later, two T-33 jet trainer pilots, flying close to Sandy Hook, New jersey, spotted a large, silvery object flying below them, which seemed to move independently. The pilots estimated the object to be 40--50 feet in diameter, with speeds of over 700 miles per hour.

A report of these sightings was submitted to the Air Force and found its way to the group responsible for investigating such events, then operating under the name "Project Grudge." Accounts of the pilots' sighting were leaked to local papers, which resulted in high-level interest in the investigative process. "Project Grudge" became "Project Blue Book" in 1952 and would continue until 1966.

The results of the "Project Grudge" investigation concluded that the Fort Monmouth sightings could be attributed to the Evans Signal Laboratory release of two balloons at 11:12 EDST September 10, which was during the time frame of the sightings. The diameter of the balloons when they burst was approximately 39 feet. The radar anomaly was attributed to user error.

The records of "Project Blue Book" have been declassified, and many differing accounts of the incident can be found online for those who are interested in continuing the investigation.

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