Planetary damage will only show up when an whole number of objects on the surface have been destroyed.
If a weapon platform has 1500 hitpoints (shields+armor+internals), you will have to fire 20 CSM1's before the damage causes an explosion animation.
If you right-click the planet in tactical, you should be able to see the damage racking up before the bLast.
Additionally, if there are planetary shields, all your shots will dissapear until the shields are breached. There used to be a planetary shield animation long, long ago, but it was the same size as the ship animation, and looked quite silly
.
Oh, and for missiles; they have to reach the far (top-right) corner of the planet before they hit. If they run out of fuel while crossing the planet, you're out of luck. The patch fixed this.
[ 27 April 2002: Message edited by: Suicide Junkie ]