✧ The Art Vault: Public-Domain Celestial Engravings, Free to Browse

954 public-domain astronomical and astrological engravings (celestial atlases, astrolabes, armillary spheres and zodiac plates) each credited to the museum that holds it, with a link to its own record. Nothing here was generated. Free, no account.

• What you'll needNothing at all
• What you getA browsable, searchable library of historical celestial art with full provenance, changing order daily
• CostFree, no account required

Umbriel harvested 1,911 artworks from five open-access collections and kept the ones whose own catalogue entries say they are celestial. The vault ships 954 of them: Andreas Cellarius, Johann Bayer's Uranometria, Doppelmayr, Alexander Jamieson, Petrus Apianus, al-Biruni's lunar-phase diagrams, astrolabes and armillary spheres.

Every plate carries its maker, date, collection and licence, and links to the museum's own record so the credit can be checked. That is not a legal footnote. It is the difference between a museum object and a stock image, and it is the reason this is worth browsing at all.

Nothing in the vault is AI-generated. Worth saying plainly on a wall of pictures. Every one is a real object in a real collection, photographed by that institution and released into the public domain or under CC0.

The sources are the Wellcome Collection, the Art Institute of Chicago, the Cleveland Museum of Art, the Metropolitan Museum of Art and Wikimedia Commons, chosen because each publishes an unambiguous open-access designation rather than merely being old.

The order changes every day and holds still within a day, so the vault is different each time you open it without a picture vanishing while you are showing somebody.

The collection was assembled from five open-access museum APIs and then filtered on subject, which is the step that matters: museum search engines RANK results, they do not FILTER them, so a query for 'comet' returns a war club as its four-hundredth-best guess and every query returns something. Judging a record by the query that surfaced it would therefore pass everything. Each item is instead scored on what the institution's own catalogue says the object IS (its title, description, classification, medium and culture) never on the search term, giving 1,430 keeps, 341 too thin to call, and a small number cut outright. The shipped 954 are then chosen round-robin across subjects, not by score, because a straight ranking returns thirty-five Cellarius plates and ninety-six pages of one atlas: one book, over and over. Near-duplicate titles are collapsed for the same reason. Provenance travels with every image (maker, date, collection, accession, licence and a link to the source record) and is never separated from it. Credit fields are cleaned, not printed raw, because Wikimedia returns Wikidata qualifiers inside the date field and, worse, sometimes returns the file's UPLOAD timestamp there: uncorrected, that dated a sixteenth-century Petrus Apianus engraving to 2025. A confidently wrong date on a museum label is worse than no date, since the reader has no way to tell, so implausible dates are dropped, not shown. Display order is seeded on the calendar day, so the vault differs each day and holds still within one.