".:"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.