Time history of the on-sky position uncertainty for the Saturnian irregular Aegir. The last observation of this moon was in 2006. The on-sky uncertainty oscillates due to the projection of the three-dimensional orbital position uncertainty normal to the line of sight from Earth. The leftmost vertical dashed line marks 2012 January, the second and third lines mark three and ten sidereal satellite orbital periods later. The envelope of maximum uncertainty grows with time, and will be about 1 4 by 2021 and nearly 3 5 by 2043.