Two days ago for 13 hours it was thought that the earth had a new moon. Identified by the International Astronomical Union’s Minor Planet Centre (MPC) in Cambridge, Massachusetts, who posted on the morning of April 27th, that a small asteroid about a metre across had been spotted in a geocentric orbit by the Pan-STARRS telescope in Maui, Hawaii. They went on to say that the object would remain bound to the Earth-moon system between October 2014 and March 2019, making it a temporary moon of our planet.
The announcement itself is not unusual, it is thought that there are hundreds of tiny moons orbiting the earth and several have been spotted in the past, usual staying in an earth orbit for a time before drifting off. The unusual aspect of this declaration was that it was retracted 13 hours after posting by the MPC, with the organisation having to admit that the new moon was actually Gaia; the European Space Agency telescope currently mapping a million stars in the Milky Way. The MPC stated “These things do exist, this just isn’t one of them unfortunately“.
This error though isn’t the MPC’s first, back in 2007, the MPC issued a warning that an object called 2007 VN84 was heading for a near-miss with Earth. It actually turned out to be ESA’s Rosetta spacecraft on a fly-by past Earth, building up enough speed for its historic rendezvous with comet 7P/Churyumov-Gerasimenko.
It is easy to laugh but the errors are very possible. The MPC monitor the space junk orbiting earth and analysis of telescopic data may throw up anomalies, especially if there are issues with luminosity, suggesting an object is not what it really is. More importantly the amount of space junk is increasing with near misses and collisions becoming more probable over time.