Since the discovery of the Tar Morden system, few gave its fourth orbiting sphere any chance of ever becoming a lively or populated world. Long ago, Tar Morden IV suffered from the same meteor swarm that also crossed Tar Morden V's path. The only difference is that Tar Morden IV has a much thicker crust, preventing impacts from penetrating it. As such, Tar Morden IV doesn't have any volcanoes like Tar Morden V does. With no viable atmosphere to speak of and a rocky surface pockmarked with the craters of myriad asteroid impacts, the planet was seemingly condemned to remain barren and devoid of life for eons to come. Yet, an ambitious but costly project changed the face of this globe over the course of the last century.

A loose affiliation of wealthy businesses and affluent individuals in the Expansion Region sponsored the large-scale construction of massive, interconnected habitat blocks across Tar Morden IV’s surface, capable of sustaining life and providing artificial gravity in what would otherwise be a frozen vacuum. Within a couple of decades since initial construction was begun, most of the planet’s surface resembled the image of a gargantuan orbital space station that had descended upon its surface and enveloped it in a tight embrace. Yet, this exterior appearance of cold metal and circuitry belied the vibrant arcologies that had arisen inside the habitat blocks.

Today, Tar Morden IV is a densely populated planet with a vibrant and diverse population of humans and aliens from across the galaxy. In large part, this is due to the widespread presence of heavy industry across the world, which was able to flourish due to the lack of a natural ecosystem and thus little to no environmental legislation. With a strong economy that managed to cover the costs of its development and even generate a modest profit, Tar Morden IV became a key economic hub within its star system.