This map shows the size and location of human-space in relation to the entire Galaxy. This is an edge-on view of the Galaxy, showing the thickness of the Galactic disc and central bulge. A top view would show the Galaxy to be circular.
Of the 40 million or so stars within human-space, about 2 million contain worlds which could possibly support life, while only an estimated 65,000 can sustain humans without life support. Humans have so far colonised only 560 of these worlds.
The table at right lists the worlds described in detail so far in the Amber Nebula campaign. These include most of the populated worlds within 30-40 parsecs of Earth. Other human worlds have names and coordinates, but no detailed campaign description yet. You can see all 560 human worlds mapped in 3 dimensions in my Interactive Amber Nebula Starmap Applet. (An example map is shown below.)
The coordinate system used is a 3-dimensional Cartesian system aligned with the x and y axes in the Galactic plane and the z axis pointing toward Galactic north. The negative y axis points from the origin (Earth) to the Galactic core.
Human-space is divided into sectors, each a cube 100 parsecs along each side. The central sector is called Earth Sector, and Earth is at the centre of it. Human-space covers all or part of some 121 sectors. Each sector is divided into 27 subsectors, each 33 1/3 parsec cubes. Sectors and subsectors are named by the Space Navigational Authority, based on Earth. Although many worlds do not recognise Earth's sovereignty over this matter, the sector names have been adopted for use by virtually all space travelers, simply for the convenience of having a standardised nomenclature.
This map shows the positions of the nearest 20 inhabited worlds to Earth, in a 3-dimensional projection. The grey plane is parallel to the Galactic plane. Earth is the green dot at centre. The two slightly confused planet names are Kariba and Arawne.