But Richard Miles made his own observations from England by controlling a telescope on Hawaii over the internet and found clues to its real identity.
The “asteroid”, detected by the Catalina Sky Survey as it made a close flyby of the Earth, has an orbit around the Sun that is similar to our own, lasting just 1.04 years.
Richard, of the British Astronomical Association, also made a series of measurements of its brightness and colour, using the Faulkes Telescope North, a mountaintop instrument mainly used remotely by schools. Its faintness and hue both indicated that the object was man-made with a coating of titanium dioxide paint rather than a space rock.
Richard, of Stourton Caundle, Dorset, believes it may be the 5.7-meter (19ft) long fourth stage of a Russian Proton rocket that launched the Luna 23 probe into orbit around the Moon in October 1974. The unmanned probe landed in Mare Crisium and was intended to bring back samples of moonrock but failed when its drilling device was apparently damaged.
It is not the first time that spacecraft have been mistaken for asteroids. There were red faces when an official alert in November 2007 turned out to be the utterly predictable flyby of Rosetta on its way, ironically, to study a couple of minor planets in the asteroid belt.
Scientist Paul Chodas, of NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory, California, said: “The orbit of this object is very similar to that of the Earth, and one would not expect an object to remain in this type of orbit for very long.”
2010 KQ is now leaving the Earth’s neighbourhood after passing just outside the orbit of the Moon. It will next come close in 2036. Experts say there is a one-in-20 chance that the space missile will enter our atmosphere but that it is too small to do any damage.
Dr Chodas said: “At present, there is a 6 per cent probability that 2010 KQ will enter our atmosphere over a 30-year period starting in 2036. More than likely, additional observations of the object will refine its orbit and impact possibilities. Even in the unlikely event that this object is headed for impact with Earth, whether it is an asteroid or rocket body, it is so small that it would disintegrate in the atmosphere and not cause harm on the ground.”
One of the Catalina Sky Survey’s previous discoveries was of a small asteroid which did enter the Earth’s atmosphere in October 2008, breaking up and showering the ground with meteorites in a remote part of the Sudan.
