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SpaceHero Atlas

Page history last edited by Michael 8 years, 10 months ago

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The Milky Way Galaxy is a spiral about 100,000 light years in diameter; the "thin disk" containing most stars is about 1,000 light-years thick. Terra (the Earth) is about 26,000 light-years from the galactic center, a flattened sphere about 1,000 light-years across -- the Hub.


Several thousand stars are concentrated in the Hub, along with dense clouds of swirling, energized gas. At the very center of the Hub is a massive black hole, with a mass 4 million times that of Terra's sun.


The galactic halo, composed of scattered older stars and globular clusters, is a sphere about 200,000 light years across. Compared with the spiral arms, the distances between stars in the halo is very large. The nearest globular cluster is about 25,000 light-years away from Terra.


The galaxy has several spiral arms; the Orion Arm contains the Sirian Principality and Terra. Around the Principality, the arm is about 2,000 light years wide and less than 1,000 light years thick.


A pair of much smaller galaxies, the Magellanic Clouds, orbit the Milky Way galaxy at less than 200,000 light years distance.


For easier space-travel calculations, all the stars can be considered to lie in a single plane. It really is a three-dimensional universe, though.


Within 200 light-years of Terra there are nearly 2,000 star systems. The map shown above shows a region of about ten billion systems.


Named stars:  Rigel, Canopus, Sirius, Antares and Deneb are all very large, extremely bright stars -- very unlikely to have any life forms native to their systems.


Nebulae and Clusters:   these areas are very turbulent, mostly either new young stars or remnants of older, exploded stars. Swirling clouds of energized gas give them an auroral appearance; but sensors don't work well in the clouds. Faster-than-light travel may also be impossible or dangerous there. The Cygnus Loop (aka the Veil Nebula) is the remnant of a supernova some 5,000 to 8,000 years ago; the gaseous remnants are speeding out from the vanished star at a few percent of the speed of light.


Voids and Rifts:  the interspiral voids (top and bottom) and the Great Dark Rift have relatively few stars -- "just" a few thousand total on the map, averaging about 50 light years apart.


Named regions:  within the Sirian Principality, there are the Outworld Colonies, the Siravan Marches, and the Central Realm. To one side of the Principality are the Glarrik Territories; and along the inner edge of the spiral arm are the Jacker Stars, home to pirates and other lawless beings.


Systems of Note:



For all the named worlds on the map, there are millions of lesser systems. Thousands, maybe tens of thousands, have intelligent inhabitants, or had them in the past. Some examples of these are:


  • ruined resource world:   Antaraxes IV, about 50 light years from Carneval.
  • currently-exploited resource world: G777BZ, near the Kelmor Cluster.
  • ancient ruins world: Horwellin, remnant of a cryptic alien culture, near the Owl Nebula.
  • agricultural world: Noxus Beta, near the Pleiades
  • minor colony: Pikru, in the Outworld Colonies.


Areas not on the map:    to spinward (left or 'west' on the map) several alien, human, and ara-human polities have formed, most notably the Bavanii Confederation. The nearest edge of the Confederation is over 2,000 light-years from the borders of the Principality. Much further away, around the rim of the galaxy, is an area of space known as the Vrogan League, an exclusively non-human organization of some sort. To anti-spinward (right, or 'east' on the map) of the Principality are the Glarrik Territories, devastated and colonized in the last few hundred years by the hideous Glarriks. Far beyond the Glarriks are the worlds of the Centrality, inhabited largely by various forms of robotic and cybernetic beings.


At the hub of the galaxy is the Core Worlds Empire, home to vastly powerful and strange beings of pure energy. Their "emperor" exists in (or as) the accretion cloud around the galactic black hole.


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