User blog comment:RandomGuy96/So how do planetary defense cannons work?/@comment-5436239-20130127223836/@comment-4967682-20130127224412

No, big ships could still dodge the projectiles just fine by parking themselves a few hundred thousand kilometers away so they can easily move out of the way of any shots.

Ships have no accuracy issues. There is no accuracy issue in space, all of the projectiles travel in a straight line. Given that all weapons are computer-aimed and designed to hit things moving out relativistic speeds, against a stationary target it should be 100% accurate.

Once again, the attacking fleet engages you at their own leisure. They could park away, bombard your defenses, and then fight your fleet at a range where the cannons would be completely ineffective.