I plopped a star base next to a wonderful black hole with 3 antimatter. I was tickled when the base started mining all 3.  Several turns later the scout came back on the other side and found a second black hole where if I placed the star base just right I could hit 4.  I destroyed the star base and a bit later built the new one.  When it started mining and you could see paths to the antimatter.  I noticed the old paths were  still there.  50+ turns later when doing some updates to the star base, the old lines are still there.