Cartography

A page covering stellar cartography in Project Daybreak.

Overview
In general, Daybreak's UNSC stellar cartography is based on the real-world galactic coordinate system, supplemented by various custom systems. Up until the post-war era, UEG astronomy is heavily Sol-centric, though this eventually changes in the Phoenix Initiative era.


 * Galactic longitude marks stars and other objects' position "horizontally" on the galactic plane, also known as the galactic equator in the context of the coordinate system. Longitude is measured in degrees, with 0° being the direction of the galactic center relative to Earth, 90° being roughly spinward, 180° directly toward the galactic rim, and 270° being pointed roughly at the trailing or antispinward direction.


 * Galactic latitude marks objects' relative position north or south of the galactic equator, as viewed from Earth; it is measured in degrees, though the most useful concepts in most cases are the galactic north and galactic south. The galactic north pole is located 90° "above" the galactic plane, while the south pole is located 90° "below" it. The corresponding Covenant concepts are "zenith" and "nadir", respectively.

The terms Coreward/Rimward and Spinward/Antispinward (or Trailing) are also frequently used to indicate directions relative to the galactic disk; these are used universally by humanity and the Covenant.

The Milky Way
The home galaxy of humanity, the Covenant species and the various peripheral civilizations they came into contact with, as well as the long-vanished Forerunners.

The Orion Arm
Also known as the Orion Spur or Local Arm, and called the Raan-Uchaal Bridge by the Covenant; the minor spiral arm housing both humanity and most of the Covenant's fixed territories. The Orion Arm was also the home arm of the Forerunners, whose core worlds were evidently located within and around a vast star-forming region and molecular cloud aggregation now known as the Orion Complex, located just over 1,000 lightyears from Earth.

The Covenant Sphere
The Covenant encompasses a large region of the Orion Arm, mainly located galactic antispinward of humanity's territories; their oldest worlds are located around 3,000 lightyears from Earth.

The Human Sphere
As of 2565, humanity's sphere of influence is still largely concentrated on a 200-light year radius within an interstellar void known as the Local Bubble.

On the large scale, human space is divided into four supersectors, or FLEETCOM sectors in UNSC military usage. These are quadrant volumes of space defined along the galactic plane, with Earth as their center point. In theory, these four sectors encompass the entire galaxy and beyond, though human space only covers a small part of them. They are similar to the modern-day concept of galactic quadrants, though their numbering is different based on Halo canon. The supersectors can be further split into "northern" and "southern" octants, though this division is often ignored for the sake of simplicity.

The Sol system and its Oort Cloud are not part of any sector and the space within a five-light year radius of Sol is simply known as SolCore.

The supersectors are further split into numerous named sectors, which radiate around SolCore in circles. The innermost ring of sectors surrounding SolCore is 20 lightyears in width and is split into eight sectors (two per supersector) while the surrounding rings are 25 lightyears wide and each have 24 sectors (six per supersector). Sectors have historically been named as the need has arisen; in the current system, sectors are named consistently up until 150 lightyears, as this marks the furthest extent of human space in most regions.

Notably, the conventional mapping system is imperfect and increasingly inaccurate the further one goes from Sol, as it does not account for the three-dimensional nature of space. Likewise, systems' distances are shown only relative to Earth, not to one another. Many systems that appear to be neighbors on the map can in fact be on virtually on opposing sides of space. One competing system is the Neutral Astrographic Scheme, derisively known as the Innie Grid due to its popularity in the colonies. The NAS uses a 3D grid of cube-shaped volumes to avoid highlighting any particular system over others. Spacers commonly use the relative distances between colonies, measured by the length of slipspace jumps, as a basis for their charts; this is rather similar to the fundamental ideas behind the Covenant's mainstream cartography. There are also other systems which base their charts on expansion waves and/or political and cultural blocs within the human sphere, but these are generally more obscure.

Human astronomy also uses the traditional constellations to mark galactic directions, especially relative to Earth and the Inner Colony sphere. The further out one goes, the more meaningless these become, though they are still used in places out of tradition. Some of the more common ones used to mark galactic longitude are:
 * 0°: Sagittarius (Roughly coreward from Earth; the radio source Sagittarius A* marks the position of the galactic core.)
 * 30°: Aquila
 * 60°: Cygnus (Roughly marks the spinward direction along the Orion Arm)
 * 90°: Cepheus
 * 120°: Cassiopeia
 * 150°: Auriga
 * 180°: Orion
 * 210°: Canis Major
 * 240°: Puppis
 * 270°: Vela (Situated virtually antispinward of Earth)
 * 300°: Centaurus
 * 330°: Norma

The Siakar Expanse
The Siakar Expanse is a former Covenant administrative territory, or primary domain. It is located some 1,000 light-years from Earth close to the Orion Complex, and is thus one of the closest Covenant territories to humanity. It is also notable as the termination point of the Pleiades Corridor, the most stable and trafficked slipspace route between the human and Covenant spheres in the post-war era.