User blog comment:RandomGuy96/So how do planetary defense cannons work?/@comment-5379655-20130128042915/@comment-5379655-20130129033648

Sidenote: The guy above me had a good point. Unless you have perfect intel on the positions of cannons, scanning range is still limited, requiring you to get close enough to scan the surface to find them or to triangulate fire coming from them, in which case you're too close anyways.