User blog comment:RandomGuy96/So how do planetary defense cannons work?/@comment-4973403-20130128220226/@comment-4973403-20130129172853

True, but if you want to occupy the planet, you will have to move in. In order to move in, you will have to deal with the opposing fleet, which can simply remain on the far side of the planet until your fleet moves in close. On the other hand, if you simply wanted to terror bomb the planet into submission, then your fleet could certainly remain at stand-off range and begin a long distance bombardment, hopefully drawing the enemy fleet out of hiding. However, as you're bombarding from a distance reinforcements are likely going to be on the way to joint he defense fleet.