{
 "v": 1,
 "fetched": "2026-10-16",
 "credit": "Moon maps: USGS mosaics of Voyager 2 images (Caltech/JPL/USGS, public domain); ring radii: NASA PDS Ring-Moon Systems Node; moon data: NASA JPL SSD; Uranus map: artistic, based on Irwin et al. 2024 true colour",
 "items": [
  {
   "id": "uranus-procedural-map",
   "name": "Uranus colour map (procedural, artistic map based on Irwin et al. 2024 true colour, Voyager 2 and Hubble 2014-2025 observations)",
   "url": "https://doi.org/10.1093/mnras/stad3761",
   "credit": "Original work for this page. Colour target: P. G. J. Irwin et al. (2024) \"Modelling the seasonal cycle of Uranus's colour and magnitude, and comparison with Neptune\", MNRAS 527, 11521, DOI 10.1093/mnras/stad3761 (Uranus is a pale greenish blue, Neptune only slightly bluer).",
   "licence": "Own work",
   "fetched": "2026-10-16",
   "transform": "ARTISTIC map, no image data from any spacecraft or telescope was used; no Bjorn Jonsson or Solar System Scope map. Built by tools/build-textures.py: 4096 x 2048 equirectangular, planetocentric latitude, east longitude, x = 0 is lon -180, y = 0 is lat +90 (IAU north). Each pixel = base colour x (latitude profile + longitude noise) + cap tint. Profile: faint zonal banding (sum of three sines, total amplitude 2 percent, periods 21, 13, 7 deg latitude); a brighter north polar cap poleward of about 60 N (smoothstep from 50 to 70 N, gain +8 percent at the pole, tint +5 R +3 G; basis: Hubble 2014-2025 shows a bright north polar cap) ; a faintly darker collar near 47.5 S (gaussian sigma 4.5 deg, depth 5.5 percent; basis: Voyager 2 dark polar collar near 45-50 S); a 3.5 percent darkening poleward of -70 (the south pole is in winter dark in 2026); low-amplitude longitudinal noise (1.2 percent, gaussian blurred 46 x 5 px, fixed seed, so rotation is perceptible up close). The map has no physical longitude anchor. All parameters: base_rgb = (172, 217, 221); cap_edge_lat = 60.0; cap_halfwidth = 10.0; cap_gain = 0.08; cap_rgb_shift = (5, 3, 0); collar_lat = -47.5; collar_sigma = 4.5; collar_depth = 0.055; band_amp = 0.02; band_period_deg = (21.0, 13.0, 7.0); band_phase = (0.7, 2.1, 4.3); noise_amp = 0.012; noise_sigma_x = 46.0; noise_sigma_y = 5.0; noise_seed = 2026; south_dim = 0.035. 2K is a Lanczos resample of the 4K.",
   "used": [
    "assets/tex/color-2k.jpg",
    "assets/tex/color-4k.webp",
    "assets/tex/color-4k.jpg",
    "assets/fallback/map-2k.jpg",
    "assets/fallback/poster.jpg",
    "assets/og.jpg"
   ]
  },
  {
   "id": "jpl-ssa-texture-maps",
   "name": "Caltech/JPL Solar System Simulator texture maps ura1vuu2 (Ariel), ura2vuu2 (Umbriel), ura3vuu2 (Titania), ura4vuu2 (Oberon), ura5vuu2 (Miranda): USGS mosaics of Voyager 2 images",
   "url": "https://space.jpl.nasa.gov/tmaps/uranus.html",
   "credit": "Caltech / JPL / USGS (mosaics by the USGS Astrogeology Science Center from Voyager 2 images, NASA / JPL); files fetched from https://space.jpl.nasa.gov/tmaps/pix/ura1vuu2.tif to ura5vuu2.tif",
   "licence": "Public domain content (USGS and NASA / JPL Voyager 2 mosaics, credit \"Caltech/JPL/USGS\" as requested on the source page). The JPL page itself states no licence text; USGS and NASA products carry no copyright.",
   "fetched": "2026-10-16",
   "transform": "TIF 1440 x 720, 8-bit greyscale, simple cylindrical, latitude +90 at row 0. The page describes them as \"from the USGS, mosaicked with Voyager imagery. Grayscale.\" Longitude convention VERIFIED by overlaying USGS Gazetteer centre points (see usgs-gazetteer): EAST positive, -180..180, lon 0 (sub-Uranus point) at the image CENTRE, so the files already have the engine orientation (x = 0 is lon -180) and are not rolled. Checked on Miranda (Arden Corona -29 N 74 E and Elsinore Corona -25 N 257 E fall on the two large coronae, Inverness Corona 326 E on the chevron; the same two coronae also fit a 0..360 reading, which the chevron rules out), Ariel (Kachina 246 E and Korrigan Chasmata 347 E on the long chasma systems), Titania (Gertrude 287 E basin, Messina Chasmata 335 E, Ursula 45 E), Oberon (Hamlet 44 E and Othello 43 E dark crater floors), Umbriel (Wunda 274 E bright ring). Only the southern part is imaged (Voyager 2 flew by with the south poles facing the Sun; about 36 to 43 percent of each map is covered). Unimaged pixels (black, value 0) and the dark ragged terminator edge (9 px eroded) are filled with the moon's mean tone: the imaged part is first scaled to a mean level L = 77 + 139 x geometric albedo (Miranda 121.5, Ariel 131.2, Umbriel 106.2, Titania 114.5, Oberon 109.0; the same rule as the Jupiter maps), the edge is extended by normalised convolution (sigma 6 px) and fades to the flat tone L over about 50 px with a 3 px feathered data edge, plus 1.5 grey levels of faint low-frequency texture so the fill is not a flat plate. No invented craters. Source resolution is only 4 px per degree: the 2K files are bicubic upsamples of 1440 x 720 and carry no more detail than the source. Greyscale stays greyscale (R = G = B); the engine tints with moons.json tint. The south polar rows are visibly stretched in the source (cylindrical projection).",
   "used": [
    "assets/tex/moon-miranda-512.jpg",
    "assets/tex/moon-miranda-1k.jpg",
    "assets/tex/moon-miranda-2k.webp",
    "assets/tex/moon-miranda-2k.jpg",
    "assets/tex/moon-ariel-512.jpg",
    "assets/tex/moon-ariel-1k.jpg",
    "assets/tex/moon-ariel-2k.webp",
    "assets/tex/moon-ariel-2k.jpg",
    "assets/tex/moon-umbriel-512.jpg",
    "assets/tex/moon-umbriel-1k.jpg",
    "assets/tex/moon-umbriel-2k.webp",
    "assets/tex/moon-umbriel-2k.jpg",
    "assets/tex/moon-titania-512.jpg",
    "assets/tex/moon-titania-1k.jpg",
    "assets/tex/moon-titania-2k.webp",
    "assets/tex/moon-titania-2k.jpg",
    "assets/tex/moon-oberon-512.jpg",
    "assets/tex/moon-oberon-1k.jpg",
    "assets/tex/moon-oberon-2k.webp",
    "assets/tex/moon-oberon-2k.jpg"
   ]
  },
  {
   "id": "usgs-astrogeology-uranus",
   "name": "USGS Astrogeology Voyager 2 mosaics of the Uranian satellites (checked for a direct global mosaic download)",
   "url": "https://fdp.astrogeology.usgs.gov/fdp/uranus/",
   "credit": "USGS Astrogeology Science Center",
   "licence": "Open data / citation only (NASA / JPL / PDS / IAU / journal pages; facts cited, text written for this page)",
   "fetched": "2026-10-16",
   "transform": "Checked 2026-10-16: the USGS Foundational Data Products page lists only 1987-1988 airbrush mosaics and control networks for Miranda, Ariel, Umbriel, Titania and Oberon, and the planetarymaps.usgs.gov / asc-pds-services S3 listings contain no Uranian global mosaic GeoTIFF. The Voyager 2 mosaics were therefore taken from the JPL Solar System Simulator copy (jpl-ssa-texture-maps), which credits the USGS. There is no full-resolution USGS global mosaic of these five moons that we could download; Bjorn Jonsson maps were not used by rule.",
   "used": []
  },
  {
   "id": "usgs-gazetteer",
   "name": "USGS Gazetteer of Planetary Nomenclature: nomenclature centre points for Ariel, Umbriel, Titania, Oberon and Miranda",
   "url": "https://planetarynames.wr.usgs.gov/GIS_Downloads",
   "credit": "USGS Astrogeology Science Center / IAU Working Group for Planetary System Nomenclature (https://asc-planetarynames-data.s3.us-west-2.amazonaws.com/ARIEL_nomenclature_center_pts.zip, and the UMBRIEL, TITANIA, OBERON, MIRANDA files)",
   "licence": "Public domain (NASA / USGS; no copyright asserted; credit as requested)",
   "fetched": "2026-10-16",
   "transform": "Shapefile attribute tables (center_lat, center_lon: east longitude, 0..360) used only to verify the moon-map longitude convention and the names in moons.json; no geometry is shipped.",
   "used": [
    "data/moons.json"
   ]
  },
  {
   "id": "pds-rings-table",
   "name": "PDS Ring-Moon Systems Node: Vital Statistics for Uranus's Rings (after Showalter and Lissauer 2006 and Nicholson et al. 2018)",
   "url": "https://pds-rings.seti.org/uranus/uranus_rings_table.html",
   "credit": "SETI Institute / NASA PDS Ring-Moon Systems Node; M. R. Showalter and J. J. Lissauer (2006) Science 311, 973, DOI 10.1126/science.1122882; P. D. Nicholson et al. (2018) The rings of Uranus, in Planetary Ring Systems, Cambridge University Press, 93-111",
   "licence": "Open data / citation only (NASA / JPL / PDS / IAU / journal pages; facts cited, text written for this page)",
   "fetched": "2026-10-16",
   "transform": "Middle radius (km), mean width (km), eccentricity and optical depth as listed: Zeta 39,600 (3,500 wide), Six 41,838 (1.53), Five 42,234 (2.28), Four 42,571 (2.33), Alpha 44,718 (8.46), Beta 45,661 (9.49), Eta 47,176 (1.6), Gamma 47,627 (2.15), Delta 48,300 (4.6), Lambda 50,024 (2.3), Epsilon 51,149 (58.1; 20 to 96 km around the orbit), Nu 67,300 (3,800), Mu 97,700 (17,000). rings.json: r = middle radius; in / out = r -/+ mean width / 2 for every ring (narrow rings and the broad dusty zeta, nu and mu alike). The older Voyager-era extents (zeta about 37,000 to 41,000 km; mu about 86,000 to 103,000 km; nu 66,100 to 69,900 km) differ from the PDS middle-and-width by a few thousand km for the broad rings. Dust sheets (Zeta CC, Zeta C, Alpha-4, Beta-Alpha, Eta C, Delta C, Lambda C) are mentioned in text but not drawn as rings. Ring 1986U2R is the zeta ring. Associated moons: Ophelia (gamma), Cordelia (delta), Cordelia and Ophelia (epsilon), Portia and Rosalind (nu), Mab (mu). Eccentricity is null where the table lists none (eta, delta) and 0 where it lists 0.",
   "used": [
    "data/rings.json"
   ]
  },
  {
   "id": "ring-discovery",
   "name": "Ring discovery: Elliot, Dunham and Mink 1977, Nature 267, 328 (nine rings, KAO occultation of March 1977); Smith et al. 1986, Science 233, 43 (Voyager 2); Showalter and Lissauer 2006 (nu and mu, Hubble)",
   "url": "https://doi.org/10.1038/267328a0",
   "credit": "J. L. Elliot, E. Dunham, D. Mink (1977); B. A. Smith et al. (1986); M. R. Showalter, J. J. Lissauer (2006)",
   "licence": "Open data / citation only (NASA / JPL / PDS / IAU / journal pages; facts cited, text written for this page)",
   "fetched": "2026-10-16",
   "transform": "disc strings in rings.json follow the contract: 1977 occultation for Six, Five, Four, Alpha, Beta, Eta, Gamma, Delta and Epsilon; Voyager 2 (January 1986) for Lambda and Zeta; Hubble 2003 to 2005 for Nu and Mu. Colours: Nu red and Mu blue per de Pater et al. 2006, Science 312, 92 (Keck and Hubble).",
   "used": [
    "data/rings.json"
   ]
  },
  {
   "id": "ring-display",
   "name": "Ring display opacity and colour (rings.json a, col)",
   "url": "https://pds-rings.seti.org/uranus/uranus_rings_table.html",
   "credit": "Original work for this page",
   "licence": "Own work",
   "fetched": "2026-10-16",
   "transform": "NON-PHYSICAL display opacity: the true reflectivity of the rings is about 2 percent (very dark), so the artistic opacities only make them visible. Epsilon 0.55 (brightest), other narrow rings 0.25 to 0.40, zeta 0.06 (reddish grey), nu 0.05 (reddish), mu 0.06 (blue). Display colours are hand-set: narrow rings neutral dark grey, epsilon #8d9196, nu #9a6f62, mu #6f93c4.",
   "used": [
    "data/rings.json"
   ]
  },
  {
   "id": "jpl-ssd-sats",
   "name": "JPL SSD Planetary Satellite Physical Parameters and Mean Elements",
   "url": "https://ssd.jpl.nasa.gov/sats/phys_par/",
   "credit": "NASA / JPL Solar System Dynamics Group (https://ssd.jpl.nasa.gov/sats/elem/)",
   "licence": "Open data / citation only (NASA / JPL / PDS / IAU / journal pages; facts cited, text written for this page)",
   "fetched": "2026-10-16",
   "transform": "Fetched 2026-10-16. Mean radius km and GM km3/s2 (URA111): Ariel 578.9 / 83.5, Umbriel 584.7 / 85.1, Titania 788.9 / 226.9, Oberon 761.4 / 205.3, Miranda 235.8 / 4.3. Mass = GM / G with G = 6.6743e-20 km3/kg/s2 gives 1.251e21, 1.275e21, 3.400e21, 3.076e21, 6.44e19 kg. Mean density g/cm3: 1.539, 1.523, 1.653, 1.664, 1.178. Mean elements (URA182, equatorial frame, epoch 2000-01-01.5) a km: 190929, 265986, 436298, 583511, 129846; periods d: 2.520379, 4.144177, 8.705869, 13.463237, 1.413479. aRU = a / 25559.",
   "used": [
    "data/moons.json"
   ]
  },
  {
   "id": "nssdc-uranus",
   "name": "NASA NSSDC Uranus Fact Sheet and Uranian Satellite Fact Sheet",
   "url": "https://nssdc.gsfc.nasa.gov/planetary/factsheet/uranusfact.html",
   "credit": "NASA Goddard NSSDCA (https://nssdc.gsfc.nasa.gov/planetary/factsheet/uraniansatfact.html)",
   "licence": "Open data / citation only (NASA / JPL / PDS / IAU / journal pages; facts cited, text written for this page)",
   "fetched": "2026-10-16",
   "transform": "Uranus: mass 86.811e24 kg (rounded 8.681e25), equatorial radius 25,559 km and polar radius 24,973 km (1 bar), mean density 1,270 kg/m3, sidereal orbit 30,685.4 d = 84.01 years, obliquity 97.77 deg. Moons: visual geometric albedo 0.32 Miranda, 0.39 Ariel, 0.21 Umbriel, 0.27 Titania, 0.23 Oberon. Minimum temperature -224 C (49 K, coldest planetary atmosphere, tropopause) from NASA's Uranus pages.",
   "used": [
    "data/uranus.json",
    "data/moons.json"
   ]
  },
  {
   "id": "moon-count",
   "name": "Known moons of Uranus: 29 (JWST S/2025 U1 announced August 2025), checked 2026-10-16",
   "url": "https://en.wikipedia.org/wiki/Moons_of_Uranus",
   "credit": "NASA / Webb (S/2025 U1, Southwest Research Institute team, announced August 2025); Wikipedia Moons of Uranus; NSSDC lists S/2023 U1",
   "licence": "Open data / citation only (NASA / JPL / PDS / IAU / journal pages; facts cited, text written for this page)",
   "fetched": "2026-10-16",
   "transform": "moonsConfirmed 29: 28 known before the Webb discovery (27 named, S/2023 U1 unnamed) plus S/2025 U1. Searches on 2026-10-16 found no later discovery. 5 major moons, 14 small inner moons (including S/2025 U1), 10 irregular moons.",
   "used": [
    "data/uranus.json",
    "data/moons.json"
   ]
  },
  {
   "id": "lamy-2025",
   "name": "Lamy et al. 2025, A new rotation period and longitude system for Uranus, Nature Astronomy",
   "url": "https://doi.org/10.1038/s41550-025-02492-z",
   "credit": "L. Lamy et al. (2025), Nature Astronomy, published 2025-04-07",
   "licence": "Open data / citation only (NASA / JPL / PDS / IAU / journal pages; facts cited, text written for this page)",
   "fetched": "2026-10-16",
   "transform": "Rotation period 17 h 14 min 52 s (17.247864 +/- 0.000010 h, from Hubble aurora images 2011 to 2022); Voyager 2 value 17 h 14 min 24 s. uranus.json dayLength carries both. The IAU W rate used by the engine (-501.1600928 deg/d) is the WGCCRE 2015 value, which is the older Voyager period.",
   "used": [
    "data/uranus.json"
   ]
  }
 ]
}