[Randallw]

If you look at the descriptions for weapons you will see an entry saying what it can shoot at.

For PD (point defence) it will say seekers. Units really, so missiles, fighters. Satellites as well.

For missiles it will say ships\planets. Satellites are units so you can't attack them.

energy weapons will say any but seekers. As a result it fires at anything but missiles. This is a bit confusing as I know they can shoot at fighters, though not with the bonus dedicated PD gets.

Edit: I really should have said direct fire weapons, not just energy weapons. This means depleted uranium

Torpedoes, though direct fire, are ships\planets like missiles.