Aberration

[Sarah]

A small periodical change of position in the stars and otherheavenly bodies, due to the combined effect of the motion of lightand the motion of the observer; called annual aberration, when theobserver's motion is that of the earth in its orbit, and dairy ordiurnal aberration, when of the earth on its axis; amounting whengreatest, in the former case, to 20.4'', and in the latter, to 0.3''.Planetary aberration is that due to the motion of light and themotion of the planet relative to the earth.

[Tracie Lynn]

something [unusual], [different] from the [norm].

[Jessica]

A departure from what is normal, usual, or expected, typically one that is unwelcome.