[Coco] Looking for CoCo astronomy and space software.

[Theodore Evans (Alex)]

On Jan 19, 2004, at 1:21 PM, jdaggett at gate.net wrote:

> Alex
>
> The only way to do planetarium style programs is to convert
> Gregorian calendar date to Julian calendar. By using Julian dates
> and scaling one can predict with some degree of certaincy the skies
> as they appeared over say the Middle  East in 10,000 BCE. Or the
> skies over New York city in 10,000 CE. In fact in 12,000 CE the star
> Vega in the constellation Lyra will be the North Star. During the fall
> in the early evening it is the brightest star in the northern skies.

There is a confusing term.  Unfortunately todays Julian date can be 
interpreted as 2453024 (the one you mean), 2004019, or 6 Jan 2004.  
While (astronomical) Julian dates are the typical way of doing such 
things, they are hardly the only way.  For example one could easily use 
a 64-bit signed Unix date.