Virus Bomb

A Virus Bomb is a potent Imperial biological weapon and weapon of mass destruction, commonly used to carry out Exterminatus actions during the Great Crusade and Horus Heresy periods of the late 30th and early 31st Millennia, most memorably during the Istvaan III Atrocity. They were largely replaced in Imperial arsenals by the more potent Cyclonic Torpedoes by the time of the late 41st Millennium, but have still been deployed in recent memory, such as upon the Stalinvast Hive World in 273.M41 following a Genestealer infestation.

Virus Bombs deploy a hideous genetically-engineered pathogen called the Life-Eater virus intended to exterminate all forms of life in an inhabited planet's biosphere. The pathogen, once released in aerosol form from the Virus Bombs, is extraordinarily infectious, capable of infecting every living thing, including flora, fauna and even bacteria on an entire world in only solar minutes if 100% orbital dispersal is achieved. The pathogen can penetrate even sealed environment suits, including Power Armour. The virus is designed to violently lyse living cells, essentially causing infected organisms to "melt" into a contaminated soup of organic matter. Entire forests can be reduced to this sludge in a short period of time, and individual animals die excruciating deaths as their bodies rapidly decay around them. The incredibly rapid breakdown of organic matter results in the rapid release of great volumes of highly flammable gas, much of it composed of methane. Eventually, as the contamination spreads across the surface of the world, a single spark, a single lightining strike, or an intentional incendiary event, will cause this gas to ignite, sweeping the planet with an apocalyptic, global firestorm. This incredible heat will scour the world's surface back to bare rock as well as eradicate most of the remaining oxygen in the planet's atmosphere if it was habitable by Terran life.

In some cases, the lifeless Dead Worlds that are all that remain of a planet that has suffered a virus bombing still prove valuable to the Adeptus Mechanicus.

Second War for Armageddon
During the Second War for Armageddon in 941.M41, Armageddon's Planetary Governor, the Overlord Herman von Strab, had maintained a secret stash of ancient Virus Bombs that had originally been collected millennia before when his family had first led the colonisation of the Hive World. Once unleashed on the invading Greenskins, the took a terrible toll, but their extreme age had degraded the stocks of Life-Eater pathogen within, and so the death rate among the Orks was no where near total. Even worse, like many biological and chemical weapons, the shifting winds caused some of the pathogen to infect many members of the Astra Militarum regiments leading the Imperial defence, ultimately leading to as many deaths among the defenders of Armageddon as among their foes.

The lifeless rocks left after a viral bombing may still contain valuable non-organic resources after the virus itself has died off. In such situations, the Adeptus Mechanicus may re-terraform the world, rendering it habitable again.[4] Related articles

Exterminatus Atmospheric Incinerator Torpedo Cyclonic Torpedo Sources

1: Galaxy In Flames (Novel) by Ben Counter, [Needs Citation] 2: The Flight of the Eisenstein (Novel) by James Swallow Chapter 9 3: Inquisitor (Novel) (1990), by Ian Watson, [Needs Citation] 4: Ice Guard (Novel) by Steve Lyons, [Needs Citation]