Credits
Night Atlas is made by me, Stephen Partridge, through Partridge Enterprises LLC. It's free to download and use. Download sites may share the unmodified NightAtlas.zip for free, as long as they link back to https://getnightatlas.com, but please don't sell it, charge for it, or change or repackage the zip. The full terms are on the license page.
Third-party notices
Pictures, catalogs, and fonts that I didn't make stay under their own licenses. The Windows download lists them in THIRD-PARTY-NOTICES.txt; please keep that file with the program.
Engine
The app is built with the Godot Engine, under the MIT license. That license covers the engine, not Night Atlas.
Stars and catalogs
Bright-star positions and magnitudes follow Hipparcos and the Yale Bright Star Catalog. Constellation stick figures follow d3-celestial by Olaf Frohn. Fainter stars, down to about magnitude 6 (roughly the faintest you can see by eye under a dark sky), come from that same star set.
The NGC and IC catalog used for searching and for matching photos to objects is OpenNGC, by Mattia Verga, under Creative Commons Attribution-ShareAlike 4.0. The sky map shows the Messier objects plus a smaller set of other well-known galaxies and nebulae, at their standard catalog positions.
Meteor-shower names, radiants, and typical peak nights follow International Astronomical Union usage. The hourly rates are typical counts under a dark sky, meant as a guide rather than a live forecast.
The descriptions that appear when you click an object are my own writing, not text from Stellarium. Sizes, distances, and moon counts for the planets follow NASA’s public facts.
The Milky Way, the figures, and the menu
The Milky Way glow is original Night Atlas art. It is not a photograph.
The constellation figures are original gold outlines in the manner of an old atlas. The Mazalot cards are original gold line drawings for the Jewish twelve and for the Tanakh names Kimah, Kesil, and Ash. The Hebrew letters use Noto Sans Hebrew, from Google Fonts, under the SIL Open Font License 1.1.
The menu picture is original Night Atlas art of a backyard session.
Planets, the Moon, and deep-sky photographs
Planet pictures are public-domain works of the United States government: NASA, JPL-Caltech, and STScI. Mercury is from MESSENGER, Venus from Magellan, Mars from Viking, Jupiter from Juno, and Saturn from Cassini. NASA did not endorse Night Atlas.
Moon phases are stills from NASA’s Scientific Visualization Studio (Ernie Wright, Lunar Reconnaissance Orbiter). The waxing crescent and the waning gibbous that open when you click the Moon are my own photographs. For the other phases, the app zooms in on NASA's picture of the Moon. NASA did not endorse Night Atlas.
The photos you see in the sky for M31 (the Andromeda Galaxy), M42 (the Orion Nebula), the Horsehead, NGC 6712, NGC 6888 (the Crescent Nebula), the Veil, and the Iris are ones I took with my Vaonis Stellina. Larger versions are in the free Photographs pack.
Telescope photos of deep-sky objects: Stephen Partridge, taken with a Vaonis Stellina smart telescope.
A few other Messier objects use Hubble and Spitzer stills from NASA, JPL-Caltech, and STScI. The rest of the Messier pictures are color images from the Digitized Sky Survey 2, by STScI and NASA, served through the Centre de Données astronomiques de Strasbourg. NASA did not endorse Night Atlas.
Towns
Town and city positions are from the GeoNames geographical database, under Creative Commons Attribution 4.0. The list includes United States places with 500 or more people, and places with 15,000 or more in other countries.