Subject: Could aliens colonise anything?

The distances are huge between stars in the rim of a galaxy. I don't know the 
average figure, but I guess it's of the order of 10 light years. I have no idea 
what the distance might be between stars with habitable planets, but let's say 
it's of the order of 100 light years. Out here on the rim, it seems pretty 
unlikely that any civilization would ever be able to colonise anything but their 
own solar system. Distances are just too great - not to get from A to B but to 
maintain a single civilization with light-years between its scattered outposts. 
In the inner galaxy there must be few habitable planets - too many binary star 
systems, too many stars, too much radiation for life. Do you think any life form 
could really colonise the galaxy? 

Re: Could aliens colonise anything?