* Astronomy

A 10-metre object on a heliocentric orbit, now catalogued as 1991 VG, made a close approach to the Earth in 1991 December, and was discovered a month before perigee with the Spacewatch telescope at Kitt Peak. Its very Earth-like orbit and observations of rapid brightness fluctuations argued for it being an artificial body rather than an asteroid. None of the handful of man-made rocket bodies left in heliocentric orbits during the space age have purely gravitational orbits returning to the Earth at that time. In addition, the small perigee distance observed might be interpreted as an indicator of a controlled rather than a random encounter with the Earth, and thus it might be argued that 1991 VG is a candidate as an alien probe observed in the vicinity of our planet.
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On November 6, 1991, James V. Scotti discovered an object, about 10 meters in size, now known as 1991 VG. The object's orbit was found to be very similar to Earth's orbit and it was found that it would make a close approach to Earth just a month after discovery. Given such an Earth-like orbit, the dynamical lifetime of such an object is relatively short with the object quickly either impacting Earth or being perturbed by Earth onto a different orbit. The similarity of its orbit with Earth is also very difficult to explain from natural sources, with ejecta from a recent Lunar impact or non-gravitational perturbations such as the Yarkovsky effect having been suggested.
The uncertainty of the object's origin, combined with rapid variation in the object's brightness in images obtained during its close passage with Earth in early December 1991, led some to argue that 1991 VG might be artificial in origin, possibly an extraterrestrial object such as a Bracewell probe, because its characteristics and orbital path seemed to rule out known space junk launched from Earth. At present, the question of its origin remains unknown, though critics suggest the artificial origin seems to not be well supported.
1991 VG has absolute magnitude H=28.5 which would correspond to an asteroid between about 6 and 12 meters diameter and it is therefore far too faint for further study, apart from during close approaches to Earth.
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The first potential Earth-impact for 1991 VG  is on the 21st November, 2101