by Fnord666 on (#4ZY4H)
New Temporary Moon in Earth OrbitJoeMerchant writes:On February 15th 2020 a magnitude 20 object designated 2020 CD3 was observed and projected to be in a 47 day elliptical orbit of the Earth. Projections do not all agree yet, but the orbit is believed to be unstable and should not last more than about 3 years. 2020 CD3 is estimated to be between 1 and 6 meters in diameter, though reportage varies wildly on the size estimates. Nobody seems to be commenting on perigee, though the simulation images suggest it is approximately at lunar orbit distance - of course with the 47 day period apogee is well beyond lunar orbit.This is only the second "captured asteroid" to be observed in Earth orbit, 2006 RH120 was observed to be in Earth orbit from September 2006 to June 2007 - although 1991 VG was weakly captured for a month in 1992 and is expected to return in the future.Many stories have already been published elsewhere - Wikipedia has already been updated; but, nobody seems to be asking the important questions like: if Pluto can be disqualified as a planet, how can 2020 CD3 be called a moon? ;-) EarthSky was unable to be consulted, perhaps due to the traffic spike, but other astronomers have referred to the object as a TCO - Temporarily Captured Object, while some question if 2020 CD3 is in fact an artificial object like a spent Apollo era booster stage.Earth has a new mini-moon -- but it's only temporaryGaaark writes: