Asteroid

Galaxy Portal

Asteroids are massive rocks in the Galaxy, that either drift through space^[1] or orbit celestial objects like stars,^[2] worlds^[3] or moons.^[4]

Description

They are formed through various means, including gravity binding star-wrought dust together for aeons,^[5] as well as being fragments of destroyed worlds.^[2] or moons.^[3] Asteroids also give off huge swathes of magnetic radiation, that can mask the approach of spaceships that closely follow them. Depending on their size, it is even possible for an entire armada to be masked by an asteroid.^[6a] Asteroid Fields can also mask a ship's presence, either due to the numerous asteroids' sizes^[7] or if they are rich in dense, sensor-opaque ores.^[3] However entering asteroid fields can be dangerous, as micrometeorites can clog spaceship engines, while ice fragments and the gravitational forces of super-dense iron asteroids can buckle their hulls.^[8] Drifting asteroids can become trapped in a celestial object's orbit^[7] and possibly reclassified as moons if they circle worlds.^[9] However, if they do so in large numbers, then these asteroids become known as Asteroid Belts^[10] and are called Elliptical Belts, if the asteroids completely encircle the celestial object.^[3]

Asteroids are common throughout the Imperium, but not many contain enough resources for it to justify mining them.^[1] Instead, the Imperium uses asteroids as colonies,^[11] platforms for weapon emplacements, orbital docks,^[4] or outposts used for its various factions, like the Missionarius Galaxia or Adeptus Mechanicus.^[2] The Imperium can also weaponize them, by installing crude engines onto an asteroid's surface.^[12] However when one does meet the threshold to be mined, the Imperium can establish communities whose whole task is to do so and the populations will make the asteroids their homes.^[13] The Adeptus Mechanicus can also extract resources from asteroids by either installing mining installations within them^[14] or by sending Mining Barges.^[1]

Asteroids are able to strike worlds, either through a natural occurrence^[15] or as part of an attack by an invading force.^[6a] When this occurs, the Imperium has technology that uses gravity to displace asteroids,^[16] as well as weapons that can destroy them. Though firing upon the asteroids can result in massive explosions, if they have highly combustible cores. In those cases, the Imperium will instead redirect the asteroid's path by striking them a glancing blow that will change their trajectory.^[6b]

The T'au also colonize asteroids^[17] and pirates^[18] of various species use them as bases as well.^[19][21][22] The Orks are well known for using their technology to displace asteroids^[16] or to turn them into bases^[20] and even Rok warships.^[21] This can make attacking these occupied asteroids difficult if they have a metal composition, as this will prevent energy-scans from providing details results of their inner workings.^[20]

Known Asteroid Fields and Belts

• Acata Ring^[24]
• Aragna Chain^[26]
• Cerberian Field^[8]
• The Girdle — Asteroid belt located in the Kalidar System.^[23]
• Kalidar's Noose — Asteroid belt located in the Kalidar System.^[23]
• Maelanel Reef — Asteroid field located in the Laevanir Archipelago.^[25]

Known Asteroids

• Asteroid 1182^[27]
• Black Rock^[6b]
• Buketown^[22]
• Burbeck's Asteroid^[20]
• Pharos^[2]

Sources

• 1: Games Workshop: Forgotten Fleets - Arenea Stalker (Saved archive page, dated 11 April 2008, last accessed 30 March 2026, original link)
• 2: The Bleeding Chalice (Novel), Chapter 7
• 3: Deus Sanguinius (Novel), Chapter 8
• 4: Iron Hands (Novel), Chapter 10
• 5: Lazarus: Enmity's Edge (Novel), Chapter 5
• 6: Nocturne (Novel):
  • 6a: Chapter 3 - II Devotion of Another Stripe
  • 6b: Chapter 8 - II Blinded
• 7: Azrael (Novel), Date Ident: 887939.M41#1312
• 8: Soul Drinker (Novel), Chapter 6
• 9: Red Fury (Novel), Chapter 5
• 10: Doubt Begets Heresy (Short Story)
• 11: Imperial Armour Volume Two - Second Edition, pg. 20
• 12: Mortarion: The Pale King (Novel), Chapter 4
• 13: The Battle of Tyrok Fields (Short Story)
• 14: Huron Blackheart: Master of the Maelstrom (Novel), Chapter 1
• 15: Warlord: Fury of the God-Machine (Novel), Chapter 2
• 16: Shadow of Ullanor (Novel), Chapter 5
• 17: Black Tide (Novel), Chapter 2
• 18: Battlefleet Gothic Magazine Issue 7, pgs. 18-23
• 19: Priests of Mars (Novel), Microcontent 08
• 20: Warhammer Siege, pg. 116 - Example Fortresses: Fort Shaggro, Burbeck's Asteroid
• 21: Blood of Iax (Novel), Chapter 2
• 22: The Alien Hunters (Short Story) — Xenos Hunters (Anthology)
• 23: Baneblade (Novel), Interstitial (after Prologue), pgs. 17-18
• 24: Imperial Armour Volume Two - Second Edition, pg. 20
• 25: Warhammer 40,000 9th Edition Rulebook, pgs. 162-163
• 26: Old Earth (Novel), Eighteen
• 27: Warhammer: Return to Cadia Trailer – Hammer and Bolter – Warhammer 40,000 (published 15.01.2025) (last accessed 30 March 2026): 00h:00m:02s