According to UFO conspiracy theorists, the Black Knight is an “alien satellite which has orbited Earth for 13,000 years”, however, the mythical object is most likely a conflation of several disconnected stories according to senior education support officer Martina Redpath of Armagh Planetarium in Northern Ireland:
Black Knight is a jumble of completely unrelated stories; reports of unusual science observations, authors promoting fringe ideas, classified spy satellites and people over-interpreting photos. These ingredients have been chopped up, stirred together and stewed on the internet to one rambling and inconsistent dollop of myth
The origin of the Black Knight legend is often “retrospectively dated” back to natural extraterrestrial repeating sources heard during the 1899 radio experiments of Nikola Tesla and long delayed echos first heard by amateur radio operator Jorgen Hals in Oslo, Norway in 1928. According to the Daily Express, “the noises from 1899 and 1928 remain a mystery, but the possible causes do not so far include an alien satellite, according to scientists.”
In 1973, Scottish author Duncan Lunan analyzed the long delayed radio echoes received by Hals and others and speculated that they could possibly originate from a 13,000 year old alien probe located in an orbit around the earth’s moon. He suggested that the probe may have originated from a planet located in the solar system of star Epsilon Boötis. Lunan later retracted his conclusions, admitting he’d made “outright errors” and characterizing his methods as “unscientific”.
In February 1960 TIME reported that the U.S. Navy had detected a dark object thought to be a Soviet spy satellite in orbit, however a follow-up article confirmed that the object was “the remains of an Air Force Discoverer VIII satellite that had gone astray”.
In 1963, astronaut Gordon Cooper supposedly reported a UFO sighting during his 15th orbit in Mercury 9 that was confirmed by tracking stations, but there is no evidence that this actually happened.Brian Dunning notes that this story appears in “virtually every UFO book about the Black Knight case”, but says that no record of such an event was given by NASA, radar station personnel, or from any contemporary source. Dunning describes the story as “purely an invention of modern writers”.
An object photographed in 1998 during the STS-88 mission has been widely claimed to be the Black Knight satellite. According to educator Redpath and space journalist James Oberg, it’s more probable that the photographs are of a thermal blanket that was confirmed as lost during an EVA.
A British rocket called the Black Knight rocket that was used in conjunction with the Blue Streak missile program between 1958 and 1965 is unrelated to the Black Knight satellite legend.