A5. The Quads - Overview

Universal Planetary Quadrangle Mapping System

Summary: Introduced to unify quadrangle systems across planetary sized bodies (spherical).  

Definition: Large continental-scale operational units composed of multiple Zands, and aligned to unified Zones and Bands definition approach (i.e. Quads align with zones and bands).

Standard: 26 Quads per planet: 24 equatorial/mid-latitude Quads (6 per belt × 4 belts) and 2 polar Quads (North, South).

Usage: Serve as the largest named reference divisions, analogous to legacy quadrangles but globally standardised across bodies.

Quad Table (ZBS / MGrid, boundary at 30°)

Notes

Quad table with the belt boundary at 30°, polar caps at ±72°, and R = 3,389.5 km.

Area method: spherical band/cap; a 60°-wide Quad is 1/6 of the full-longitude band. Height = meridional arc; Avg width = Area ÷ Height.)

Per polar cap (≥ 72°): 3,533,019 km²; height 1,064.84 km; average “width” ≈ 3,317.88 km.

Per 60° low-latitude Quad (0–30°): 6,015,475 km²; height 1,774.74 km; avg width 3,389.50 km.

Per 60° mid-latitude Quad (30–72°): 5,426,638 km²; height 2,484.63 km; avg width 2,184.08 km.

Totals:

12 low-lat Quads × 6.015 M = 72.19 M km²

12 mid-lat Quads × 5.427 M = 65.12 M km²

2 polar Quads × 3.533 M = 7.07 M km²

Grand total ≈ 144.37 M km² (matches 4πR24\pi R^24πR2 with R = 3,389.5 km).

Why 0°-30°-72°@6° Structuring of Quads

Adopted 0°–30°–72° @ 6° to create a clean, planetwide grid with six 60°-longitude quads per band.

Delivers 24 sub-polar bands (12 per hemisphere), neatly aligning with our 24-zone framework.

Low-latitude quads = 5 bands tall; mid-latitude quads = 7 bands tall—this pairing yields similar-sized sub-polar quads for easier comparison and planning.

Adds finer zoneband granularity in 30–48°, the expected initial settlement belt (three stacked bands).

Keeps the 30–48° region within a single 60° quad, avoiding cross-quad fragmentation.

Produces compact, well-proportioned polar caps (72–90°) without distorting mid-lat shapes.

Key Benefits of the Universal Quads & Zones-Bands vs Multiple Legacy Schemas

Cross-Planet Compatibility: One coding framework applies to all spherical or near-spherical bodies: planets, moons, dwarf planets, large asteroids. Eliminates body-specific quadrangle schemes.

Consistent Quad Counts Across All Planets: Every planetary body is divided into 26 Quads, regardless of size. Simplifies multi-world navigation and cataloguing of the largest divisional unit.

Integration with Timekeeping: 24 longitudinal Zones correspond directly to planetary time zones. Enables direct coordination between geospatial codes and planetary calendars or shift systems. All sub-polar quads span 4 time-zones.

Scalability: Quads = continental administrative units. Zands (zone × band) = mid-scale, near-equal area blocks. Supports both fine-grained science (Zand codes) and coarse governance (Quad codes).

Alignment: The longitudinal boundaries of the mid and lower latitude quadrangles align so the adjacent boundaries are simpler. 

Similar Areas in Sub-Polar Regions: All sub-polar quads are within ~10% of each others area.

Standardised 6° Latitude Bands: Uniform divisions enable clean nesting: Quads → Zands → Provinces → Sectors → Tiles → Clicks. Avoids arbitrary or politically influenced latitude lines.

Flexible Numbering: Quads are numbered systematically: 01 = North Polar, 02–13 = northern belts, 14–25 = southern belts, 26 = South Polar. Zands can be encoded compactly as [Zone][Band]. Codes can be paired with cultural or settlement names without breaking reference integrity. Or in case of Mars a simple Greek alphabet scheme can be adopted.

Historical Neutrality: Not tied to any one space agency’s cartography. Provides a politically neutral “tabula rasa” for planetary mapping and settlement.

Planetary Legacy Quadrangle Mapping Systems

Quadrangle mapping divides planetary surfaces into manageable, rectangular sections for detailed cartographic and geological work. Despite the spherical nature of these bodies, quadrangle schemes vary depending on mapping history, mission needs, and surface coverage rather than planet geometry.

Moon (Lunar Quadrangles)

Number of Quadrangles: 30 quadrangles at 1:2,500,000 scale (144 at 1:1,000,000 scale)

Naming/Numbering: Labeled LQ01–LQ30 (large-scale), arranged from north to south; higher-resolution uses LAC series, with names based on prominent features

Lat–Lon Boundaries: Large scale: Bands like 65°–90° N (pole), then 30° increments in latitude. Fine scale: 12 latitude bands; longitude divisions vary with latitude

Logic: Early photographic mosaics and variable-size features required varying density; polar zones require fewer quadrangles due to longitude convergence.

Mercury (Hermes Quadrangles)

Number of Quadrangles: 15 quadrangles (H-1 to H-15) 

Naming/Numbering: “H” stands for Hermes; named after craters or albedo features—originally based on remote telescopic data, updated post-MESSENGER 

Lat–Lon Boundaries: Each covers 22° latitude bands: ±21° around equator, mid-latitude sectors up to ±66°, and one polar cap each. Longitude typically spans 90°, except equatorial zones.

Logic: Tailored to match mission imagery—reflects data availability and regional feature visibility.

Mars (MC Quadrangles)

Number of Quadrangles: 30 (MC-01 to MC-30)

Naming/Numbering: MC = Mars Chart; named after classical albedo/geographic features (e.g., Mare Boreum, Tharsis)

Lat–Lon Boundaries: 16 equatorial quads: 0–30° latitude × 45° longitude. 12 mid-latitude quads: 30–65° latitude × 60° longitude. 2 polar quads: ≥65° N or ≤65° S, full 360° longitude 

Logic: Balances map size, feature resolution, and latitudinal distortions; historically rooted in manageable mapping units for geological surveys.

Venus (V-Quadrangles)

Number of Quadrangles:  8 at 1:10,000,000 scale. (62 at 1:5,000,000 scale)

Naming/Numbering: Designated V-n, named for Venusian features (e.g., Ishtar Terra)

Lat–Lon Boundaries: Broad lat bands (e.g., 0–57° N, 57–90° N) with full longitude. Finer scale slices: variable latitude bands (25° or 50°) and 30° longitude sectors.

Logic: Reflects Venus’s thick cloud cover and the need for radar mosaics; variations accommodate distortions and feature density.

Cross-Planetary Comparison