The Imperials hail from the third of the five major moons of a gas giant about three times the size of Jupiter, which orbits a K-class star at a little less than one AU.
The first moon is, of course, the most geologically active of the five. Despite being only a little over a fifth (22%) the Earth's mass, it has a dense atmosphere and a surface gravity of about 6.2 m/s^2. While whatever water it posessed during its formation was boiled away long ago by the heat produced by its primary, a subsequent collision has added a considerable amount, and in the current day it is a stifling, wet world of perpetual cloud cover and near constant rains. There's much less seasonal or regional variation than on most worlds, because of the way the cloud layer traps and redistributes heat, and pretty much the entire surface is covered by shallow, vegetation-clogged seas and swamps interspersed with volcanic outcroppings. The native civilization consisted mostly of independant city-states, each operating off of a single 'mountain' and trying to exercise hegemony over its immediate neighbors. Local technology was relatively advanced before they were conquered, roughly in the earlier stages of their industrial revolution.
The second moon was also close enough to have been boiled mostly dry, but didn't have the same later collision. Except for three small, shallow, utterly toxic seas, it has no surface water to speak of, and only limited aquifers. Aside from the lands downwind of those seas and the couple of mountain ranges tall enough to scrape moisture out of the higher parts of the atmosphere, the entire planet is taken up by the worst sort of desert. What life there is in the deep sands tends to center around an endemic species of tree whose seeds are sufficiently massive to allow a shoot to send down a root the hundreds of feet needed to find water... sometimes... These trees live a long time and grow to truly massive - if scraggly - dimensions, and can support entire semi-symbiotic ecosystems, including humans. It has the highest gravity of the moons - 6.8 m/s^2 - and is about thirty-five percent Earth's mass. Given how meager their margin of survival was, it shouldn't be any surprise that the native inhabitants never got much past, at best, a degree of sophistication comperable to what you might build on a remote pacific island.
The third moon is the largest, both by mass and volume, and the most earthlike, being a bit over half the mass and having nearly nine-tenths the surface area, along with actually more dry land... if only marginally. Most of its landmass is concentrated into a single continent, and the political system that eventually controlled the entire system developed in the high central mountain ranges before moving down onto the lowland plains. I say 'political system' because its closest analogue in Terran experience were the Inca, and the usual term of 'empire' doesn't quite fit, or anyway didn't to start with. Eventually, around abouts the equivalent of the turn of the twentieth century, one of the lowland polities got the idea of conquering and exploiting one of the non-main-continent civilizations whose existence had been known of for some time, on the theory that they'd be easier marks than any of their better-armed neighbors and provide an increased resource base for further competition. The other lowland nations promptly copied the idea, which left the highlanders in a bit of a pickle, since they were landlocked. Eventually, though, one of their scientists hit on the idea of going up.
On the one hand, this idea was a lot more expensive than just building ocean ships, but on the other, these were far more potential resources available than just a measly island or two. The competing kingdoms eventually saw this and started going offworld themselves, but never really caught up. By the time they started getting intersteller visitors, the core empire had just started to reap the benefits of a former policy of exporting the 'malcontent' of the defeated competing kingdoms to the other four moons, and thus has a call for a steady diet of security troops.
The fourth moon's notable characteristic is how much water it has - enough that the shallowest part of its world-girdling ocean is still more than a kilometer and a half deep. Being a goodly distance out from the radiant heat of the primary world, it's relatively cool, and is warmed mostly by the local sun and internal tidal action. Surface gravity is a shred under 6.4 m/s^2, and, thanks to a floating coral-anologue, there's actually a respectable amount of habitable land. Since the stuff only grows underwater and in sunlight, the form of the smaller 'islands' is a very distinctive hollow shallow cone. Larger islands - which can approach continent scale - will have a rising outer ring surrounding a jumble of sharply angled plates of stone that have caved in, then been grown into place at usually fairly strange angles thanks to the newly available sunlight. Local civilization never got past about the bronze age, thanks to the difficulty of finding materials.
The fifth moon has relatively limited geothermal activity - since all of its major stresses tend to come from the same direction and are more distant besides - and receives little extra infrared radiation. Naturally, this makes it more than a bit chilly - each of its polar ice caps covers about a third of the total surface of the planet, and much of what's still exposed is ocean. Aside from the various hunting tribes eking out their existences on the more livable parts of the ice belts, the entire planet was ruled by a powerful, centralized empire that had originally been established a century or two ago by the first of that world's kingdoms to develop gunpowder.
Politics and technology coming when I feel up to it.
Ja, -n
===============================================
"Puripuri puripuri... Bang!"
The first moon is, of course, the most geologically active of the five. Despite being only a little over a fifth (22%) the Earth's mass, it has a dense atmosphere and a surface gravity of about 6.2 m/s^2. While whatever water it posessed during its formation was boiled away long ago by the heat produced by its primary, a subsequent collision has added a considerable amount, and in the current day it is a stifling, wet world of perpetual cloud cover and near constant rains. There's much less seasonal or regional variation than on most worlds, because of the way the cloud layer traps and redistributes heat, and pretty much the entire surface is covered by shallow, vegetation-clogged seas and swamps interspersed with volcanic outcroppings. The native civilization consisted mostly of independant city-states, each operating off of a single 'mountain' and trying to exercise hegemony over its immediate neighbors. Local technology was relatively advanced before they were conquered, roughly in the earlier stages of their industrial revolution.
The second moon was also close enough to have been boiled mostly dry, but didn't have the same later collision. Except for three small, shallow, utterly toxic seas, it has no surface water to speak of, and only limited aquifers. Aside from the lands downwind of those seas and the couple of mountain ranges tall enough to scrape moisture out of the higher parts of the atmosphere, the entire planet is taken up by the worst sort of desert. What life there is in the deep sands tends to center around an endemic species of tree whose seeds are sufficiently massive to allow a shoot to send down a root the hundreds of feet needed to find water... sometimes... These trees live a long time and grow to truly massive - if scraggly - dimensions, and can support entire semi-symbiotic ecosystems, including humans. It has the highest gravity of the moons - 6.8 m/s^2 - and is about thirty-five percent Earth's mass. Given how meager their margin of survival was, it shouldn't be any surprise that the native inhabitants never got much past, at best, a degree of sophistication comperable to what you might build on a remote pacific island.
The third moon is the largest, both by mass and volume, and the most earthlike, being a bit over half the mass and having nearly nine-tenths the surface area, along with actually more dry land... if only marginally. Most of its landmass is concentrated into a single continent, and the political system that eventually controlled the entire system developed in the high central mountain ranges before moving down onto the lowland plains. I say 'political system' because its closest analogue in Terran experience were the Inca, and the usual term of 'empire' doesn't quite fit, or anyway didn't to start with. Eventually, around abouts the equivalent of the turn of the twentieth century, one of the lowland polities got the idea of conquering and exploiting one of the non-main-continent civilizations whose existence had been known of for some time, on the theory that they'd be easier marks than any of their better-armed neighbors and provide an increased resource base for further competition. The other lowland nations promptly copied the idea, which left the highlanders in a bit of a pickle, since they were landlocked. Eventually, though, one of their scientists hit on the idea of going up.
On the one hand, this idea was a lot more expensive than just building ocean ships, but on the other, these were far more potential resources available than just a measly island or two. The competing kingdoms eventually saw this and started going offworld themselves, but never really caught up. By the time they started getting intersteller visitors, the core empire had just started to reap the benefits of a former policy of exporting the 'malcontent' of the defeated competing kingdoms to the other four moons, and thus has a call for a steady diet of security troops.
The fourth moon's notable characteristic is how much water it has - enough that the shallowest part of its world-girdling ocean is still more than a kilometer and a half deep. Being a goodly distance out from the radiant heat of the primary world, it's relatively cool, and is warmed mostly by the local sun and internal tidal action. Surface gravity is a shred under 6.4 m/s^2, and, thanks to a floating coral-anologue, there's actually a respectable amount of habitable land. Since the stuff only grows underwater and in sunlight, the form of the smaller 'islands' is a very distinctive hollow shallow cone. Larger islands - which can approach continent scale - will have a rising outer ring surrounding a jumble of sharply angled plates of stone that have caved in, then been grown into place at usually fairly strange angles thanks to the newly available sunlight. Local civilization never got past about the bronze age, thanks to the difficulty of finding materials.
The fifth moon has relatively limited geothermal activity - since all of its major stresses tend to come from the same direction and are more distant besides - and receives little extra infrared radiation. Naturally, this makes it more than a bit chilly - each of its polar ice caps covers about a third of the total surface of the planet, and much of what's still exposed is ocean. Aside from the various hunting tribes eking out their existences on the more livable parts of the ice belts, the entire planet was ruled by a powerful, centralized empire that had originally been established a century or two ago by the first of that world's kingdoms to develop gunpowder.
Politics and technology coming when I feel up to it.
Ja, -n
===============================================
"Puripuri puripuri... Bang!"