The antisun point moves east in ecliptic longitude by approximately one degree per day, however in the all-sky plots, it is always fixed at the center of the page. Instead, targets appear to move west (left to right on the plot) relative to the fixed antisun as time increases. The locus of points of constant antisolar angle ("beta angle") are shown as concentric circles expanding outwards from the antisun point. This makes the plot a very convenient method for finding groups targets with similar beta angles.
Shaded areas are regions of the sky that are outside FUSE's nominal pointing range (i.e. beta angle is too high or too low, or target is in the ram).
Just as with ground based observatories, targets east of the antisun (left side of plot) tend to have night-into-day visibility, while targets west of the antisun point (right side of the plot) have day-into-night visibility. Targets in the middle of the plot have uninterrupted visibility throughout orbital night.
Dashed gridlines show meridians of equatorial longitude and parallels of equatorial latitude. Like fixed targets, the entire equatorial grid moves left-to-right as time increases.