An orbital-motion visualisation application. It displays Keplerian orbits using an intuitive graphical interface, for both satellite dynamics and planetary astronomy. Orrery displays solar system bodies including the sun and planets, minor planets, and our moon, as well as earth satellites and stars. It
is optimised for classroom presentation, but may also be used to determine visibility, look angles, and ground tracks. Orrery allows both plane projections and perspective views, with either user-selected view angles or automatic tracking.
Orrery requires system 7, and this first release is only for PowerPC. It uses about 530K of disk space, and needs about 2 Mb of RAM to run comfortably. With a large monitor or with several windows open, 4 Mb is better.