Cyclonic torpedo
Cyclonic Torpedoes are a weapon utilized by the Imperium for planetary attacks from space. Though their exact power is unknown, it is thought that they are capable of causing major damage to the structure of a planet. Though the image shown implies that only one may be needed to destroy a planet, it has been used in conjunction with other weapons for orbital bombardment; one such instance was the world Cyrene. Being unconventionally powerful, they are used exclusively for when an Exterminatus has been invoked.
The only factions within the Imperium known to have these weapons are the Inquisition and Astartes, though the Inquisition is the only power with the authority to order an Exterimatus.
Two-stage Torpedoes
A more exotic version of the cyclonic torpedo. Though the warhead is still the same, the delivery system is radically different. Instead of exploding on impact, this device will burrow though a planet's surface with a Melta charge, and detonate at the core. This will destabilize a planet, and will shatter that world in many cases. They are used against worlds that are devoid of atmosphere of biological life, such as Necron Tomb worlds.