User blog comment:RandomGuy96/So how do planetary defense cannons work?/@comment-5436239-20130127223836/@comment-5436239-20130128000607

I'm guessing that the majority of raiders and the like have significantly less firepower. Although from space they could still bombard the area, they wouldn't do that because they have a target. Once in Orbit they could but, unless they are of Blue Sun or Eclipse's capabilities, they likely have less firepower. And by incapable of destroying them, I didn't mean that exclusively. I was just taking into account of different scenarios.

PDCs could have shields around them, but like you said, bombardment would still render them a pile of rubble. However, that gives the defense chance to prepare themselves. We also don't know what kind of cannon this is, does it fire slow moving slugs or ultra light projectiles that would take them out in the blink of an eye.