Mars

Mars, also known as "The Red Planet," is the first and greatest Forge World of the Imperium of Man located in the Sol System of the Segmentum Solar, producing vast numbers of weapons, vehicles and other advanced technology for the Imperium and its war efforts throughout the galaxy. Mars is also the homeworld and headquarters of the Adeptus Mechanicus and a planet sacred to the faith of the Cult Mechanicus, which is one reason why travel to the Red Planet for Imperial personnel who are not members of the Mechanicus and share its peculiar faith is restricted.

Mars is encircled by a massive conglomeration of thousands of drydocks and other starship manufacturing facilities in a geosynchronous equatorial orbit that is known as the Ring of Iron. It was the shipyards of the Ring of Iron that constructed the vast exploratory and expeditionary fleets of the Great Crusade in the late 30th Millennium and even today produce the majority of the Imperial Navy's capital ships.

It is possible that Mars is also the world where the ancient and terrible C'tan known as the Void Dragon has chosen to slumber the eons away.

History

Mars is the twin planet of Terra, and one of many long-inhabited colony worlds located near the Cradle of Humanity. It is the homeworld and primary power centre of the Adeptus Mechanicus, the ancient and byzantine priesthood of the Machine God, and the heart of their galaxy-spanning monopoly on human science and technology. Following the Unification Wars in which the Emperor of Mankind defeated the techno-barbarians of Terra and reunited humanity's homeworld under a single government, he concluded the Treaty of Mars (known as the Treaty of Olympus within the Mechanicus) with the Cult Mechanicus to unify both Terra and Mars under the umbrella of the newborn Imperium of Man in the late 30th Millennium. The Mechanicus recognised the Emperor as the Omnissiah incarnate and swore to lend their technology, the mighty war machines of their Titan Legions and all of their production facilities to the purpose of His Great Crusade to reunite all the scattered worlds of Mankind beneath the rule of the Imperium. In return, the Emperor promised the Mechanicus that it could maintain its political autonomy on Mars and all of its other Forge Worlds and that it would remain immune from adherence to the atheistic doctrine of the Imperial Truth. This ensured that the Adepts of the Mechanicus could still maintain their faith in the Machine God. Therefore, Mars is just as important to the Imperium's survival as Terra itself, a reality reflected in the emblem of the two-headed Imperial Aquila, one head for Terra, the other for the Red Planet.

Terraforming of Mars c — Mechanicum Historical Map of Mars, *circa* M30; the terraforming that had transformed Mars into a habitable world during the Age of Technology was slowly undone by the rampant industry of war during the Age of Strife

Mars c — Mechanicum Historical Map of Mars, *circa* M35; as forge temples and manufactoria sprawls spread further over the millennia, the air became toxic, the seas slowly dried up and the deserts turned barren once more

In ancient times, Mars had a fully terraformed atmosphere and ecosystems very similar to that of ancient Terra during the Dark Age of Technology, but the constant warfare of the Age of Strife and the later rapid industrialisation of the surface after the Mechanicum secured total control over the world destroyed Mars' manufactured oxygen-nitrogen atmosphere and restored the Red Planet's surface to its primordial desert state, absent surface water and breathable oxygen. The only inhabitable regions of the planet are now the Adeptus Mechanicus' hive cities.

More than any other human-settled world, Mars possesses huge repositories of technical knowledge. Its immense libraries and databanks are highly eclectic and disorganised; one delving for secrets may find a crystal storage device containing vital genetor-level data tucked inside a scrollprint for militarised locomotives. The planet itself is a wilderness of polluted ochre desert broken by metropolises the size of tectonic plates. Here the rockcrete spires, marble arches and flying buttresses of a standard Imperial world are joined by corroded steel, iron ventilation chimneys and shining glass pipes. Extensive travel tubes pass above crackling tesla coils that power construction sites and ancient industrial wastes alike. Shining new buildings braced with riggings of steel contrast with shattered condensation traps and the ruins of millennial wars. The older districts are dotted with broken plasteel slabs and twisted girders, the occasional solitary tower pointing purposelessly toward the Martian sky.

Mars is strictly stratified in its social order. The Red Planet is ruled over by the Adeptus Mechanicus' Fabricator-General, and he possesses almost every known piece of Standard Template Construct (STC) technology or designs currently in Imperial hands. This is ostensibly so he can construct better and more durable vehicles and technology for the Imperium, although it is fairly clear that the Mechanicus is simply hoarding them. The lowest social level consists of the citizens, mainly unaugmented human populations who labour en masse at simple tasks such as sorting isotope scrap, tending hydroponics, breaking ore, stoking forges and so on. Most citizens aspire to gain status by joining the Skitarii Legions. In the process, they will receive their first battle-grade bionics and perhaps a way of later entering the priesthood of the Machine God. Lesser citizens may sport tattoos and piercings suggestive of such bionics, but dress in common work clothes -- filthy coveralls, rad-tabards or cabled environ-suits. Regardless of station, Martians have a tendency to be burly, saturnine and shaven headed, usually with a temper to match their dour aspect. All sport electoos -- subcutaneous cyberware that ranges from code-patches through which personal data is monitored to thick veins of electric cabling. Through these electoo circuits can the glory of the Omnissiah be channelled. In times of great strife, the masters of Mars' populace can use these interfaces to turn even the most gormless hab-worker into a dauntless warrior of the Machine God.

It is also rumoured that the most powerful of the C'tan, the Void Dragon, sleeps somewhere beneath the surface of Mars, in the Noctis Labyrinth, and its presence may be the reason why Necron starships briefly landed on the Red Planet in 997.M41. Should the Void Dragon awake, the very heart of the Imperium will tremble.

Planetary Data

Mars Tharsis Map — Map of Mars' Tharsis region at the time of the Horus Heresy in the early 31st Millennium

Mass: 6.42 x 10²³ kg
Diameter: 6787 km
Mean density: 3940 kg/m³
Escape velocity: 5000 m/sec
Mean distance from Sun: 1.524 AU
Rotation period: 1.026 solar days
Revolution period: 686.98 solar days
Obliquity: 25°
Orbit (inclination degree): 1.85°
Orbit eccentricity: .0.093°
Max. surface temperature: 310° K
Min. surface temperature: 150° K
Visual geometric albedo: 0.15
Highest point on surface: Olympus Mons
Atmospheric components: 95% carbon dioxide, 3% nitrogen, 1.6% argon
Surface materials: basaltic rock and altered materials

Geography

Mars Red Planet — Key locations of Mars, the first Forge World

Map Key

Glaivid Hive
Oxygos Hive
Olympus Undae Hive
Hyperboreae Undae
Collegia Titanica
Mare Chronius
Tantalus Hive
Milancovic Fusion Reactor
Arcadia solar collector fields
Omnid Apertura
The Grand Temple of the Omnissiah
Mareotis Forge Temple
Acheron Fosse Forge Temples
Arsia Mons
Fabricator-General Forge Temple
Temple of the Frictionless Piston
Temple of All Knowledge
Deep core mines
Ascraeus Mons
Dodecai Elevatus Prime
Dodecai Elevatus Secundus
Imperial Navy assembly yards
Esperanos Space Port
Deus Manus Space Port
Ipluvien Maximal
Fortress temple of Knight House Taranis
Pavonis Mons
Imperial Navy Mars Docks
Xanthos
Fortress temple of Legio Tempestus
Noctis Labyrinthus (Anathemor)
Haunted Dunes of Solis Planum
Candor Casma
Varnalia
Mondus Terrawatt II complex
Lybia Montes forge temples
Lethe Zone
Antionradi Forge Temple
Mondus Gamma Forge Temple
Mechavitae Forge Temple
The Rust Wastes
Cthonia
Autonoct Deserts
Sornia
Nilosyrtis Hive
Sydonian Tetrahedra
Protoservitor Cradle
Sydonian Mistsea
Sydonian Mask
Acidalia Planitia
Sea of Iron Curses
Vastitas Borealis

Places of Note

High Altar of Technology - Within the Temple of All Knowledge is the High Altar of Technology -- a vast database containing the knowledge of the Tech-priests. Even today every new discovery is dedicated to this altar. Every temple on Mars and throughout the other Forge Worlds is connected to the High Altar by means of a living Transmat link, a psychic Servitor whose mind co-joins all altars of the Cult Mechanicus into one holy machine entity.
Librarius Omnis - The Librarius Omnis is a vast subterranean, continent-spanning repository of knowledge located in the labyrinthine catacombs of Mars. Over the millennia, it has been the subject of several Techno-archaeologist expeditions. It was here, at the dawn of the Imperium, that the legendary Techno-Archaelogist Arkhan Land led an expedition with the intention of finding an intact, complete and still-functioning STC database. Though he was unsuccessful in this endeavour, he did make two other discoveries which revolutionised Imperial technical thinking for millennia to come -- a near complete dataslab image of STC information on what would come to be known as a Land Raider, and information on rare anti-gravitic plates, and theories on their uses, which eventually led to the construction of the first "Land Speeder."
Libarium Omnissiah - The Librarium Omnissiah is a large repository of knowledge said to contain large, mile-long logi-stacks which contains records of thousands of mysteries of the universe. It is said to rival even the archive-catacombs of the Adeptus Terra.
Mondus Occulam - Mondus Occulam was a powerful Forge Temple located in the Tharsis region of Mars. At the dawn of the 31st Millennium, it was one of the largest and most productive Forge Temples on Mars, surpassed by only Olympus Mons in size. Like many forges at the time, it was geared for war production -- exclusively manufacturing arms, equipment and Power Armour for the Legiones Astartes spread across the galaxy during the Great Crusade. As a result of their size and productivity output, Forge Master Zagreus Kane was made Fabricator Locum, the second highest-ranking individual of the Mechanicum, responsible for assisting the Fabricator-General with the governance of Mars. This particular forge was also responsible for the training of Space Marine Legionaries to become Techmarines. Only Mondus Gamma forge, under the mastery of Lukas Chrom, could replicate the quality of training offered by Mondus Occulam, but they could not match Mondus Occulam for the sheer quantity of well-trained Techmarines coming out of their forge. Following the outbreak of hostilities between the Dark Mechanicum and those Tech-priests still loyal to the Throneworld during the Schism of Mars, Mondus Occulam was one of the few forges that escaped total collapse when Chaotic scrapcode was unleashed throughout Mars' communication networks. Elements of the Imperial Fists, under the commander of First Captain Sigismund, managed to make planetfall and secure the forge's armour and weapons supplies. Despite the protestations of Fabricator Locum Kane to save his forge, Sigismund ordered the evacuation of Mondus Occulam when over sixty Traitor Titans launched an overwhelming assault on the forge.
Noctis Labyrinth - The Noctis Labyrinth is a region of Mars that lies between the Valles Marineris and the Tharsis Uplands. In Low Gothic, the name translates as "Labyrinth of the Night." It is here, deep beneath the Noctis Labyrinthus, that the fearful entity, known only as the Dragon of Mars in Mechanicus legend, sleeps for eternity. This being may be the C'tan known as Mag'ladroth the Void Dragon, who was imprisoned there by the man who became the Emperor of Mankind millennia prior to the dawning of the Age of Strife and is watched over by a single guardian, a Terran girl named Dalia Cythera, who has guarded it since the Schism of Mars during the Horus Heresy. It would be another 10,000 standard years before a new guardian would be drawn to the Noctis Labyrinth to take Dalia's place.
Olympus Mons - Known also as the "Grand Mountain" to the Titan Legions of Mars, Olympus Mons is the largest mountain on the Red Planet and is the site of the largest and most productive Forge Temple. This is the seat of the ruling Fabricator-General of Mars. It is also here, that the largest structure on Mars -- the all-important Temple of All Knowledge -- lies within the massive city.
Ring of Iron - The Ring of Iron is the name given to the massive, ring-like orbital constructions that turn above the Martian equator. Spacecraft and other large starfaring constructs are constructed within the Ring's extensive orbital factories, and many of the starships of the Battlefleet Solar are based in its huge floating docks.
Temple of All Knowledge - The Temple of All Knowledge is the holiest place on all of Mars. Within the temple's plasteel shell, shining pistons hold the vaulted roof almost a Terran mile above. The shafts of each prism are so constructed that they move to raise and lower the roof, altering its acoustic properties to accentuate the hymns of praise sung to the Machine God. Within is the High Altar of Technology, the vast database containing all knowledge of the Tech-priests of Mars. Despite the massive Warp rift known as the Great Rift dividing the Imperium in two since 999.M41, the Temple of High Knowledge still receives messages daily which are down-loaded into the High Altar -- fleeting reports from the other Forge Worlds across the galaxy, data from recovered machines, conformations of new discoveries or desperate pleas for help.
Tharsis - Tharsis is the region of Mars that surrounds the capital at Olympus Mons. During the early years of the 31st Millennium, it was one of the most productive and abundant on all of Mars and was home to a number of powerful Forge Temples. By the late 41st Millennium, holding mastery of a Tharsis-based forge was still considered a valuable position for a member of the Cult Mechanicus.
Vaults of Moravec - The Vaults of Moravec were a depository of forbidden knowledge and techno-arcana founded by Primus Moravec of the Brotherhood of Singularitarianism, who sought to hasten the creation of a technological singularity which would create an artificial intelligence greater than human intelligence. Located on the Mechanicum's holy world of Mars in the Segmentum Solar, it was hidden in a sealed vault inside a maze of old tunnels and chambers nearly a kilometre deep beneath Olympus Mons -- the mighty forge of Fabricator-General Kelbor-Hal. The Vaults of Moravec had been deliberately kept locked by the Emperor of Mankind who correctly judged the knowledge it contained as too dangerous to be known publicly. When the Warmaster Horus Lupercal began to plot his rebellion against his father, he promised Kelbor-Hal to lift the Emperor's ban on the forbidden knowledge stored there, thus swaying this powerful figure to his service. The opening of the Vaults of Moravec would spark the civil war inside the Mechanicum that would become known as the Schism of Mars and mark the true birth of the Dark Mechanicus.

Mars Military Forces

Legiones Skitarii

Skitarii Cohort1 — A Skitarii Cohort of Mars

Mars' Skitarii Legion is the most glorious of all its kind. Its warriors consider it a great privilege to wear the ancient heraldry of the Red Planet, and are fiercely defensive of their Forge World despite its unchallenged position of power in the Cult Mechanicus. Perhaps because of the acquisitive nature of their masters, the red, silver and black of Mars' War Cohorts is a common sight in each Segmentum of the Imperium. Each Skitarius is but a single cog in a war machine that spans the entire Imperium. Controlled by the neurosync imperatives of their masters, the Skitarii are organised into War Cohorts capable of overcoming any foe. They work in glorious concert, every footstep or twitch of the trigger finger optimised to further the cause of the Cult Mechanicus. The original maniples that crossed the desert reaches of Mars on foot were armed only with Galvanic Rifles. They escorted their masters from north to south across an equatorial belt infested with cannibal Servitors and rogue machine intelligences. As the centuries marched past, these escorts were refined over and over again until they evolved into the Battle Maniples of the late 41st Millennium. Many variants have been codified, from the Maniples Automata of the Legio Cybernetica to the teeming Auxilia Ordinatus, but the core fighting formation remains the War Cohort.

Like its fellow Forge Worlds, Mar's Skitarii Legion is divided into a number of macroclades, which are in turn broken down into cohorts and maniples. The vast majority of Skitarii War Cohorts are not borne into battle by armoured machines or aircraft, but simply stride to the front line without stopping, even should they have to start the journey solar months in advance of their allies. They will wade through poisonous swamps and bubbling lakes of tar to arrive at the front line on schedule, rank upon rank of Skitarii marching around chains of Onager Dunecrawlers in imitation of Mars' nomadic caravanserais. Their tireless pace echoes the constancy of their dutiful souls -- it is said that a Skitarius would rather walk himself to death than disobey a direct imperative.

Mars Forces Appearance

Mars Iconography

The holy cog-and-skull of Mars, the Cog Mechanicum, graces many Martian Skitarii warriors and vehicles, a reminder that all must play their part in the greater war machine of the Adeptus Mechanicus.

Mars Forge World Colours

Like other Forge Worlds, Mars maintains its own Skitarii forces to protect its interests, annihilate the enemies of the Tech-priests, and fight at the vanguard of the Quest for Knowledge. The Skitarii cohorts of Mars wrap themselves in flapping crimson robes which are reminiscent of the rolling toxic deserts of their homeworld. Long ago, this was doubtless a means of camouflage among the ruddy landscapes of the Martian wilderness, but it has since become a symbol of the might of the Adeptus Mechanicus across the length and breadth of the Imperium. Adorning the hems of these crimson robes and the sculpted chest plates of the Skitarii are ancient symbols and icons, each one heavy with meaning sacred to the Cult of the Machine God.

A Mars Skitarii Alpha proudly displaying the colours of his Forge World

Skitarii Vanguard and Skitarii Rangers alike wear combat robes emblazoned with the icon of their Forge World. Skitarii infantry usually have their squad number emblazoned upon the hem of their robes for easy identification, while Sicarian Princeps and Skitarii Alphas bear their unit's maniple sigil, and sometimes a skull marking their status as overseers. Lower-ranked Sicarians often bear no markings other than the colours of Mars. Some specialist units, such as Sicarian Ruststalkers and Infiltrators, may wear a number on their helm or chestplate. The armour plates of Skitarii vehicles are the same hue as those worn by the Legion's Sicarians.

The Tech-Priests Dominus of Mars may wear variants of their Forge World's heraldry, but always incorporate the dull silver of industrial sprawl, the matt black of scorched carbon residue, and the deep red of the Martian sunrise. The Electro-priests of Mars wear robes the deep red colour of their home planet, in keeping with the traditions of the Cult Mechanicus. Congregations may be distinguished by different decorative metals or markings upon their robes. Each Kastelan-class Robot is a totem of the Omnissiah's might and so is accorded a unique recognition symbol, commonly borne upon the knee and shoulder. Maniple sigils may also be applied to robots and the armour of their attendant Legio Cybernetica Datasmiths.

Sources

Codex: Adeptus Mechanicus - Skitarii (7th Edition), pp. 22-27, 55-64
Codex: Adeptus Mechanicus - Cult Mechanicus (7th Edition), pp. 6, 8-9, 25-26, 36-38, 52, 60-66, 68, 70
Codex Imperialis (2nd Edition), pg. 42
Codex: Necrons (3rd Edition), pg. 11
Horus Heresy: Collected Visions, pg. 369
Imperial Armour Volume One - Imperial Guard & Imperial Navy, pp. 81, 160
Skitarii Painting Guide - Legions of the Omnissiah(2015), pp. 3-19
The Horus Heresy - Book One: Betrayal (Forge World Series) by Alan Bligh, pg. 16
Titan Legions (2nd Edition), pg. 10-13
Warhammer 40,000: Rulebook (8th Edition), pp. 25, 27, 33, 40-42, 48, 50, 60, 73-74, 277-279
Warhammer 40,000: Rulebook (5th Edition)
White Dwarf 246 (UK), "Steel Chariots - The Space Marine Land Raider"
White Dwarf 178 (UK), "The Titan Legions," by Rick Priestley
Mechanicum (Novel) by Graham McNeill
The Beast Arises (Series):
- The Hunt for Vulkan (Book Seven) (Novel) by David Annandale