Jupiter

Jupiter is Sol's yard-world, a gas giant whose orbital docks have thrown Navy hulls from one-man interceptors to Emperor-class battleships since the Crusade. Jovian void-clans kept ship-lore even the Mechanicum did not share, and the Caul of scrap still rings the forges. Perturabo seized the moon-cloud in the Solar War and left pirates, Night Lords, and Emperor's Children to terrorise it; later Custodes and the Ordo Malleus purged heretic yards in orbit.