Empirical Limits on the Russell Conjecture

Abstract

The Russell Conjecture states that there is an unproven possibility of small (<1 m) hollow heat-resistant objects (HoHOs) in Earth orbit or otherwise present in the inner solar system or asteroid belt. While such objects are not the current target of any ongoing searches, we can place stringent limits on their presence using current optical and infrared surveys. The high albedo of HoHOs partially compensates for their small size. As such, we find that no HoHOs greater than 10 cm in radius to a distance of at least 30,000 km, by the Air Force Space Surveillance System. Objects of that size in a stable orbit at 384,000 km (the Earth-Moon distance) may be detected and confirmed by more infrequent, deeper sweeps of the same system. However, it remains possible for undetected HoHOs to exist in near-Earth or Martian orbit. We discuss the prospects of finding such HoHOs in the near future with new telescopes such as LSST.