Question on visibility of orbit changes

Mark Borg (
Sat, 14 Feb 98 09:37:24 +0100


I have a question to ask (I hope it is not off-topic...)

I believe that when an interplanetary probe (e.g. the Mars Pathfinder) 
is launched, it is first placed in a parking earth orbit.  Assuming such
a craft is low enough and large enough to be visible with the naked eye,
when the time comes for it to leave earth orbit, will an observer on earth
standing in the right place and at the right time, see the change in
In fact, right now the Apollo missions came to my mind.  Did someone see
such events when they left earth orbit?.


Mark Borg