Abstract
Three main topics were discussed in this chapter. Perturbation is the tendency of larger astronomical bodies to alter the orbits of smaller objects which stray too close to the larger entity. Lost asteroids are a class of asteroids previously tracked but now lost to asteroid trackers. Their present location is unknown. Finally, it was documented that there is an increasing number of NEOs, asteroids and comets.
Keywords: Adonis, Aethra, Barcelona, CDC imaging, Euphrosyne, Faye’s comet, giant molecular cloud, Hermes, Hidalgo, Lick, Lowell Observatory, Midas, Mirelle, Mount Wilson Observatory, Olympia, perturbation, Schmidt telescope, Sisyphus, Troilus, Zerlina.