Programs and Tables from +4000 to +2800

".:"oè a y it seem s that almost everybody possesses a microcomputer. Both amateur astronomers an -:= rese archers seek out programs or deta.iled algorithms to make astronomica.I calculations and ther - lively interest among historians as to what the night sky looked like in the distant past. Arnon g as tronomica! computations, the problem of obtaining the positions of the planets for any give par ticularly difficult. lndeed , while the computations for finding the date of Easter of a give ea.r or the locai siderea! time are rather easy, even on a. programmable pocket calculator, the calculatio - anetary positions is much more difficult. For example , when calculating the positions of Jupiter an .2- -rn their mutual perturbations must be considered.