The Electric Astrolabe

The Electric Astrolabe is a fully animated planetarium software in the form of a planispheric astrolabe. The singular advantage of the astrolabe display is that it shows most of the sky, both visible and invisible, on a single screen.
Unlike a static instrument, The Electric Astrolabe can be set for any location, date and time and includes accurate positions of the Sun, Moon, and planets. In addition, The Electric Astrolabe includes over 150 stars which can be displayed as constellation asterisms and all of the Messier objects.
Either a north or south projection can be shown. You can also display the phase of the Moon, Jupiter’s moons, Saturn’s rings, lunar eclipses and the phases of the planets at any time. The color of the sky above the horizon changes from blue, through twilight gray to black depending on the position of the Sun.
Also included are an animated orrery showing the planetary orbits and several text screens giving accurate solar, lunar and planetary positions, a help screen and several screens for customizing the program to your location and choice of colors and making it easy to use.
Text entry screens are implemented as a sort of astronomical spreadsheet. That is, changes to a value cause all related to values to be updated automatically.