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Armchair astronomers, casual observers, and archaeo-astronomers will rejoice with the use of Planet Finder. No longer is it necessary to carry around printouts of an ephemeris. Now you can explore the heavens, compare ancient observations, or just find out when the Sun goes down, right in the palm of your hand. No need to perform lengthy calculations by your hand calculator - Planet Finder does it all for you.
Planet Finder's calendar does not rely on the Operating System date system so you can browse any date in history. A word of caution though, the position algorithm (like any) gets increasingly inaccurate as the date gets very far from the present. Observations in Ptolemy's Almagest dating 150 AD have come very close to what Planet Finder will give you. It is fair to say that the algorithms are usable for 3000 years from the present. The current algorithm is accurate to one arcminute within 300 years of the present, outside of that maybe as much as a degree? Of course Pluto is about 15 times more inaccurate since we have only been watching it for about a quarter of its orbit.
Planet Finder is an astronomical calculator for the Newton 2.x operating system. It has been tested on an MP2100, please let Prism Research know if it operates on any other machine including NOS 1.x. The application is divided into two parts, the engine (AstroLib) and the interface (Planet Finder). AstroLib is a powerful prototype of astronomy routines that can be imported into any application. Planet Finder will not operate unless AstroLib is loaded onto the Newton first.
Planet Finder is released as Honorware, i.e. if you have honor, you will pay Prism Research US$10 for the two years of research it took to put this little application together. An update will be continually released here as long as people have honor. There are no passwords or obnoxious windows popping up.
In the future, Prism Research intends to write other astronomy and astrology applications which utilize the existing AstroLib library of routines.
Download the fully working copy here(50 kB .sit.hqx file) or the packages AstroLib and Planet Finder (.pkg files)
To view the existing set of known issues read this text.