Man made object found circling the Sun

Amazing what we can find out with just reflected light. [Link]

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.