freebsd-ports/astro/wmmoonclock/pkg-descr

This is a WindowMaker dockapp which displays a graphical representation of
the phase of the moon, plus additional astronomical data such as
rise/set times, orbital data, orbital elements, etc (if you click on the
image multiple times).

Probably most of the data is not that useful, but what the heck :)

WWW: http://nis-www.lanl.gov/~mgh/WindowMaker/DockApps.shtml