Sky imagery and data

Milky Way image: ESO/S. Brunier. Earth surface: NASA Blue Marble (December 2004). Night lights: NASA/NOAA (2012 composite). These are static source maps, not live cloud observations.

Stars and constellation figures use d3-celestial J2000 data. Initial direction uses a representative device-time-zone region, not GPS or an exact observing location. Star and line emphasis is a visual identification effect.

Earth cloud and ocean material

Static cloud density and water mask: Solar System Scope / INOVE, based on NASA imagery, CC BY 4.0. Adapted into a 4096 × 2048 two-channel material. Clouds evolve through slow illustrative advection and density changes of a static source composite with no supplied observation timestamp; they are not current weather. Approximate atmospheric scattering, cloud relief and ocean reflection are rendering effects. Surface and night maps remain static NASA composites; sunlight uses current UTC.

Land-only city emission

Coastline © OpenStreetMap contributors, ODbL-1.0. Simplified global coastline snapshot from an unofficial osmdata.org mirror (Last-Modified 2026-11-03), combined with Natural Earth public-domain lakes. Adapted mask database is available under ODbL-1.0. Static shoreline source, not current tides or live electricity use. License and notices, exact source and derivative metadata, reproduction builder. The worldwide raster grid is 1/256 degree (about0.43km north-south); sub-grid islands and coastal pixels have finite precision.

d3-celestial

Source and attribution

Copyright (c) 2015, Olaf Frohn
All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.