For the past week Richard Miles (BAA) has been following an as-yet unidentified object orbiting the Sun (dubbed 2010 KQ), using Faulkes Telescope North.
Recent observations suggest it is a man-made object with an exciting past.
This apparent asteroidal body was discovered by the Catalina Sky Survey on May 16. Follow-up astrometry showed it to be orbiting around the Sun every 1.04 years and that it would pass within 1.28 lunar-distances of the Earth on May 21. The object was suspected of being man-made since its orbit is very circular and of very low inclination but its orbit has not been linked to any particular launch.
Richard used the Faulkes Telescope North to perform photometry with five filters on May 25 referencing the color measurements to that of an ordinary S-type asteroid, (755) Quintilla, which was less than 1 degree away from the direction of this very close-approaching object. The color evidence and the excessive faintness of the object indicates it is man-made. In particular comparing the colors to those of the asteroid, it looks to brighten far too much as you move from the red part of the spectrum into the near infrared part. Asteroids tend to darken or at most be uniform in brightness across this spectral region (r’ filter to Z filter). Furthermore, the object was almost 4 times fainter than predicted if it had been a typical asteroid on 25 May. Preliminary checks of its orbit have not as yet revealed any candidate spacecraft during the past 30 years or so although it looks to have made a close-pass in 1975.
Further work has shown that the spectral characteristics observed using the FTN are consistent with UV-aged titanium dioxide paint. This further supports the idea that it is man-made.
Richard believes it could be the 4th stage of the Russian Proton rocket which launched the Luna 23 lunar sample return attempt. The lunar probe was launched on 1974 October 28 and reached lunar orbit on 1974 November 2. NEODyS (which you can use estimate the orbital path of Near Earth Objects) has the closest approach to the Earth of 2010 KQ on 1974 November 5 at 0.000027 AU according to yesterday’s NEODyS orbit update. The 4th stage would have been the Block D or possibly the Block DM stage equipped with an 11D-58S engine. It was 5.7 meters in length. Strangely, the latest astrometry from yesterday has changed the orbit solution a little and the 1974 Nov 5 approach has been removed. Since the empty booster is very low mass compared to its size, effects not related to the gravitational pull of the Sun and other planets (such as solar radiation pressure) can make exact calculations very difficult.
We look forward to hearing more from Richard about the progress of this strange looking object. Well done Richard!