Re: [Phys-L] astro resource

[John Denker <jsd@av8n.com>]

On 02/20/2015 10:47 AM, Anthony Lapinski wrote:
> Do you know a resource that can show me what the night sky and planets
> looked like 25K - 30K years ago? 

So the key idea is, you want to extrapolate the proper motion.

You can google for it:
  https://www.google.com/search?q=planetarium+OR+ephemeris+%22proper+motion%22

I found this:
  http://www.clearskyinstitute.com/xephem/help/xephem.html

I have no experience with it, but it seems to have a good 
reputation as a quality freeware planetarium system.  It 
seems to know about proper motion.

There are probably many others.