Silver Age Beyond
Solar Systems of the Milky Way Galaxy
Solar System Names
Commonly, but not always within the Galactic Imperium, Star Systems are named after the primary planet in the systems that sustain life. A given system may contain many worlds, and occasionally multiple habitable worlds or moons.
Solar System Features
A solar system may contain one or more stars, multiple planets, (either habitable or uninhabitable), each with almost any number of moons, spacestations or other orbiting features such as comets, as well as asteroid belts and often a jump gate at the edge of the system (if it contains a habitable planet).
The most important or primary planet in the system (for which the system is likely named) may have several listed features unique to the habitable worlds within the greater galactic civilization at large, such as the ruler of a given planet, the sect of religion represented by the primary or most important Cathedral on the planet, details about the location of the planet’s Agora, or primary business and trade zone (usually a certain city on the planet contains it’s Agora, and it is often, but not always in the capital of the world.) The political capital of the world is also listed, if there is one. Also the rating of any garrison that is known to patrol the system, the number of jump routes available from the system’s jump gates, the general tech level of the system, populations of Posthumans and alien races if available and any resources and exports the system is known for.
Distances Inside a Solar System
Distances inside a solar system are shown in AU, or Astronomical Units. An astronomical unit is a method that astronomers use to measure large distances in the Solar System. 1 astronomical unit, or 1 AU, is the average distance from the Sun to the Earth. The Earth’s orbit around the Sun is actually elliptical. It varies from 147 million km to 152 million km. For the purposes of our game, 1 AU will average out to 150 million km. The speed of light is 299,792,458 meters per second (m/s) or moving the decimal, 299,792 kilometers per second (km/s) (or about 300 km a second, rounded up for ease) which means that at the speed of light, 150 km per second, (Hyperflight 1) Starships can travel about 2 AU per second, or from Earth to the Sun and back once. Hyperflight speeds over galactic distances are discussed in the book, but I’ve included some details when speaking about Sectors as well. Handily, each level of Hyperflight is an increasing multiplier of how long it takes to travel 1 AU, so it actually breaks down pretty easily into simple terms, but I’ve displayed the math anyway for ease. at the bottom of these descriptions. 1 AU is also the average distance from a G-type yellow star to the middle of it’s ‘Goldilocks zone’ as well.
Some specific ideas to think about:
- The average jump gate is at the edge of any given solar system, about 50-100 AU from the star it orbits. So you can think of a solar system as a disk about 100-200 AU across in any direction with the system’s star or stars at the relative center and the jump gate at the edge.
- Travel at superluminal (Hyperflight) speeds inside a Solar System is actually pretty snappy, but the distances are still objectively vast.
- At sub-light speeds, it takes much longer however (even at Flight 10).
- It behooves most starship pilots to leave a bit of distance between a landable planet and not attempt to land at light speed, through the atmosphere barrier, because velocity damage at hyperflight speeds is frigging uncalled for.
- In the Galactic Imperium, ‘speed to jump gate’ is a common stat that starship builders and captains care about. That’s defined in game terms by how many AU (150 million km) per round a ship can move in-system.
|Hyperflight Level||Speed multiplier||AU per round||Notes|
|1||1 x Lightspeed||1||It takes about 50-100 rounds to get from a jumpgate to the star|
|2||10 x Lightspeed||10||It takes 5-10 rounds to get from a jumpgate to the star|
|3||100 x Lightspeed||100||It takes a round to get from a jumpgate to the star|
|4||1K x Lightspeed||1K||Everything takes at least a round in game terms, but travel is pretty close to instant.|
|5||10K x Lightspeed||10K||Same as above.|
As you can see, once you get past drive 3, it takes a single round to get anywhere in a 200 × 200 AU solar system. (Technically a round is 10 seconds, I’m aware, but these speeds are fast enough without adding an additional x10 multiplier to them!). Keep in mind that Starships, space travel and Starship Engines are complex and powerful pieces of machinery, that often must travel through the intrinsically hostile void of space, so there’s more involved in space travel than simply saying ‘Engage’. Expect Navigation, Mechanical and Electrical checks prior to any major travel, each which take at least a round to perform.
Temperature Zones Inside a Solar System
Depending on the luminosity of the star at the center of a solar system, there are definable zones of temperature: Hotter near the star and cooler away from the star. Temperature zones can vary wildly from star to star, but I don’t intend to spend a lot of time considering that aspect of a solar system. Sufficed to say, there are hot zones close to the star and cold zones farther from it, here’s some of that terminology.
|Supertorrid||The supertorrid zone is extraordinarily hot. It includes epistellar orbits (close orbits) around sunlike stars, and can be described as the region where the ambient temperature ranges from several hundred to over two thousand Kelvin. At the inner edge of the zone, solid bodies are hard-pressed to survive in an environment where even iron is more commonly found as a vapor. Toward the outer edge, temperatures edge toward the reasonable and more commonly found molecules can existing gaseous state. Mercury patrols the outermost edge of Sol’s supertorrid zone.|
|Torrid||The torrid zone covers the region of space where it is impossible for water to exist in liquid state on planetary surfaces. Life in such blazingly hot regions is all but impossible, but these worlds are often rich in metals and other geological wonders. Venus inhabits the torrid zone.|
|Temperate||The temperate zone is the place where many, but not all, life-bearing planets are found. It’s relatively easy for water to find surface regions where it can exist as a liquid, and in doing so allow life to exist. Lying in the temperate zone is no guarantee of a pleasant climate, however; just the potential. Earth and Mars lie within the temperate zone.|
|Frigid||Beyond the balmy climes of the temperate zone lies the frigid zone. Surface water cannot exist as a liquid, and can be as hard as rock on these worlds. Naturally habitable environments are only possible under extreme conditions, such as tidally-induced volcanism, massive atmospheres or just completely artificial environments. Life, if it can exist as all, has to be inventive to survive the bitter cold. Most terrestrial bodies have a greater ratio of ices to rock among these worlds than in the warmer regions. As a result, bodies are often bigger than their mass would suggest. Jupiter dominates the frigid zone of Sol.|
|Superfrigid||The superfrigid zone is a realm of deep cold, where the temperature never rises above 100 Kelvin. In extreme environments, even nitrogen can freeze solid and turn to snow. Sol’s superfrigid zone is dominated by Saturn and the ice giants Uranus and Neptune.|