(Eric Burgess’s CELESTIAL BASIC is a collection of astronomy programs originally written for the Exidy Sorcerer computer. These programs were rewritten for the Apple II and published under the above title in 1982 by Sybex. In 1983 another rewrite adapted some of the more important programs to Timex Sinclair BASIC. The result was MORE USES FOR YOUR TIMEX/SINCLAIR 1000: ASTRONOMY ON YOUR COMPUTER, 20 programs which run on the TS 1000, ZX 81, and Spectrum computers.)
PLANET FINDER plots the positions of the sun, moon, and planets for any date, time, and location. The solar system objects are shown within an area of the sky approximately 30 degrees wide by 30 degrees high – a size appropriate to the display of one zodiacal constellation at a time. The “window” on your monitor screen is nearly identical to the field of view of a 35mm camera.
The user first enters local longitude. Then the time for the display is requested: year, month, and date. Local time information is not necessary. The display is based more on the actual configurations of the celestial bodies than on the circumstances of observation.
The conventions used to identify the object to be viewed are as follows: Venus through Pluto are identified by their initial letters. The sun is an “O”, and Mercury is a “+” sign to avoid confusing it with Mars. The moon is shown as a “)” regardless of its phase.
The first display shown is a brief table of data recalling the display date, the object chosen, and its right ascension and declination (the astronomer’s longitude and latitude). An opportunity is given to COPY the screen information before continuing with the sky display.
The graphic display which follows repeats the date and object information along with the name of the zodiacal constellation in which the desired objecy is found on that date. Below this information is the view of the sky. The graphic depiction of the constellation is good enough that experienced observers would have no trouble recognizing it even if it were not identified. The object is displayed in its proper position within the constellation, along with any other planets which happen to be in the same area of the sky. Once again the option to COPY the screen is given. The the user is asked whether the display of another planer or date is desired.
The program can be typed in from the Sybex book, or a tape ($12.00) is available to eliminate hours of typing, proofreading, and editing. Contact Sybex Inc., 2344 Sixth Street, Berkeley, CA 94710 for the book. For the tape and an occasional “Celestial BASIC User’s Newsletter,” write directly to author/developer Eric Burgess at 5 & T Software Service, 13361 Frati Lane, Sebastopol, CA 95472.