Planetary Weapons

[ckotchey]

I'm still a newbie, and am wondering about the usefulness of planetary weapons (napalm bombs, radiation bombs, etc.). Namely, in my limited amount of play, even the smallest of weapons (DUCs, etc.) seem to do plenty of damage to a planet's population on their own, so why would I opt for planetary weapons when any off-the-shelf weapon seems to work just as well, and has the added benefit of being able to hit other ships?