Running 1.5.1 on Slackware 12.1, KDE interface.
This really is something I stumbled on, not really a practical issue.
I accidently pressed the 'k' key continuously instead of some other key, and Celestia crashed on me.
This is repeatable.
The time indicator goes:
,000,000x slow (??)
,000,000,000x slow (??)
Running through gdb with enable-debug=ll reveals nothing (application closed normally).
Reading the code I see that the time reduction should be stopped if < MinimumTimeRate (static const double MinimumTimeRate = 1.0e-15) - but it appears not to happen.