Note: In addition to the information presented here, students should refer to the Emperor's Hammer System Manual located at https://www.emperorshammer.org/sysman/ or on the Emperor's Hammer Wiki. As of July 2022, the System Manual was being migrated to the Wiki.

Thor is much like Ghenna in that it is an extremely frigid world, little more than an icy rock lashed by arctic climates, fierce storms scouring the surface in fronts hundreds of kilometers wide. The planet is largely unexplored due to the particularly turbulent atmosphere, the extreme weather patterns disrupting even starship sensors, whilst all attempts made to utilize probes have ended in failure - the fragile constructs incapable of surviving for long in the extreme conditions. Imperials have found no natural resources on the planet to date, despite the hope that the crust may contain pockets of ore deposits.

The only official documentation known to exist is a study of the native Grenfels, a humanoid alien species whose very existence on the barren rock is a mystery, who seem to have adapted to the planet's harsh environment by surviving the worst conditions in deep caves where the warmth of the crust has allowed basic life to develop. Published by a relatively unknown scientist, an Auroran professor of anthropology by the name of Searl Darwaen, it is theorized that the grenfels, a squat, shaggily furred race, evolved from a life form not native to the system, seeded there in the depths of history . It is believed that the Grenfels are a nomadic people, often appearing to follow variations in the crust of the planet, moving from cave to cave, invariably in areas where depth and geothermal heat combine to make a barely inhabitable environment and the ubiquitous bacterial life forms flourish. These migrations involve family groups moving rapidly across the icy surface in short journeys, the weather and climate often taking a heavy toll before they settle again.

The world has often been used by criminal elements for clandestine meetings, relying on the inability to scan the planet or its immediate area. In the past, Imperial vessels have encountered numerous private vessels attempting to conceal themselves in high orbit. While it is believed that Thor may well be a key component of the smuggling routes throughout the sub-sector. Regardless of the truth of this the navy maintains a heavy patrol within the system at all times.