[TML] average stellar intervals

[Anthony Jackson]

rpg wrote:
> Mind you spacing between star varies enormously!
> About 130 parsecs away is the Pleiades cluster containing over 3000 stars in
> an area about 13ly accross.

Open and globular clusters have rather closely packed stars. However, 
they are unlikely to have planetary systems of interest:

Globular clusters are mostly very old red dwarf stars with low 
metallicity (which are unlikely to have habitable planets), and any 
planetary systems are likely to be disrupted by gravitational 
interactions with other stars.

Open clusters are mostly very young stars, which may well have planetary 
disks, protoplanets, or even young planets, but are unlikely to have 
planets old enough for life. They also have a disproportionate 
likelihood of being uncomfortably close to a supernova.