+Whether to display a star field. Default yes.
+.TP 8
+.B \-grid | \-no-grid
+Whether to overlay a latitude/longitude grid over the map. Default yes.
+.TP 8
+.B \-flat
+Display a flat-colored map of the Earth. This is the default.
+.TP 8
+.B \-satellite
+Display a day-time satellite map of the Earth.
+.TP 8
+.B \-image \fIfile\fP
+An image to use for the day-time map.
+.TP 8
+.B \-image2 \fIfile\fP
+An image to use for the night-time map.
+The two images can be the same: the night-time one will be darkened.
+.TP 8
+.B \-frames \fInumber\fP
+The number of frames in the day/night animation. Default 720.
+Larger numbers are smoother, but use more memory.
+The day/night animation happens if \fIimage2\fP is set, or
+if \fIframes\fP is greater than 1.