Wen destroyed, the defender loses a hefty amount of its stored resources, with the attacker gaining the same amount plus a bonus that is based on the time passed since the previous incursion. Attacking fleets can store up to 500% of the normal cargo capacity this way.
Note that merely damaging this module does not result in any resource transfer; it must be fully destroyed for resources to be stolen.
Basically the same as that of the Storage Module. Do note that Antimatter Silos get extra health but lower maximum mass than Storage Modules at levels XIII and above.
Antimatter colliding with ordinary matter is known to explode in cataclysm. Oddly enough, when destroying Antimatter Silos, no such explosion occurs. (The amount of Collateral Damage is merely that of ordinary Storage Modules)
Additionally, the quantity of Antimatter stored in these modules, as well as the amount required for the various tasks in the game, are more than sufficient to destroy a planet.