User blog comment:RandomGuy96/So how do planetary defense cannons work?/@comment-4950455-20130127221231/@comment-4967682-20130127231043

No, you don't have to ignore the defending fleet. Say you and a defending fleet are duking it out at a million kilometer away from a planet. The projectiles from the cannons would take minutes to reach you. Fire a few accurate shots at the planet while dodging their fire and the defending fleet's fire. It's extremely easy to be both, as space is very big. Unless ships have some arbitrary limit about how often they can move to dodge; like moving out of the way of the cannon's attack would leave you vulnerable to a ship that shoots you right after. Even that wouldn't work, considering how much time it would take for the projectile to actually reach you.