The North West Cape Black Sphere

North West Cape is in Western Australia. In 1973 it hosted the US Naval Communication Station Harold E. Holt, a very-low-frequency station 6 km north of Exmouth. Commissioned in 1967, it was renamed for Prime Minister Harold Holt in 1968.

The Yom Kippur War was under way in October 1973. According to researcher Bill Chalker, citing Richard Hall's The Secret State, US bases in Australia had been on alert since 11 October. On 25 October the United States went to DEFCON 3. "North West Cape was used to communicate the alert to both conventional and nuclear forces in this region."

That evening, about 19:15, Lt Commander Moyer of the US Navy was driving south on Murat Road toward Exmouth. Chalker describes him as the base's deputy commander, and Moyer reported 11 years in naval aviation as an aerial gunner and radar operator. The sky was "absolutely clear at the time" when he saw "a large black, airborne object," hovering about 5 miles west and some 2,000 feet up. "After about 20-25 seconds the craft accelerated at unbelievable speed and disappeared to the north." There was no noise or exhaust, and he reported, "Have never experienced anything like it."

About five minutes later, fire captain Bill Lynn stopped his Fire Department pickup outside the Officers' Club in Area B. He had come to close it. Over the hills due west he saw "a large black object, which I at first took to be a small cloud formation." But there were no clouds. The sky was "clear & pale green-blue."

It was "a black sphere hovering." About 30 feet across, roughly 1,000 feet up. Completely still, except for "a halo round the centre which appeared to be either rotating or pulsating." No lights or sound. After about four minutes, "it suddenly took off at tremendous speed and disappeared in a northerly direction in a few seconds."

Both accounts went onto standard RAAF Unusual Aerial Sighting forms with handwritten statements and sketches. Around 1975, the RAAF passed ten pages to Sydney group UFOIC through researcher Moira McGhee. The official forms surprised Chalker.

In 1982 Chalker was given access to the RAAF's UFO files in Canberra, but North West Cape was not there. "So they'd been obviously removed at some point," he told the ABC in 2024, "but we clearly knew that there was evidence for this case." No official assessment has ever been found. In CAUS v. NSA, a 1980 lawsuit, the NSA filed a classified affidavit referring to "a 1973 report." Chalker suggested it might be this incident, but that link remains his speculation.

In 2013 Keith Basterfield reviewed the original forms. Drawing on Allan Hendry's The UFO Handbook, he asked whether a flock of birds should be ruled out first. He noted that the sun was already 11.5° below the horizon, and that the two witnesses' bearings could not be reconciled as one object seen at one time. Chalker disagreed. Trained observers would tell flocking birds from a stationary object, he argued, and a flock holding still for about four minutes would be extraordinary.

Moyer has never been traced. Lynn was an Australian citizen employed by the US Navy as a fire fighter. A commenter identifying as his son said he "was adamant that it was 'swept' under the carpet." Chalker's view is unchanged. "What was seen by the deputy commander of the base and the fire captain was way beyond any kind of aircraft, drone or whatever may have been available to the military at that time."