GAIA Mary: A Project Hail Mary Star Map Built on 1.8 Billion Real Stars

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🛠️ GAIA Mary Star Map

What it isInteractive 3D star chart inspired by the Project Hail Mary navigation UI
PlatformWeb browser
PriceFree
Linkvalhovey.github.io/gaia-mary · HN discussion

I finished Project Hail Mary wanting the stellar chart from the movie on my screen, not a static screenshot. GAIA Mary is Val Hovey’s answer: a browser map where you spin through local space, jump between named stars, and toggle views that separate real astronomy from story fiction. Val posted it on Hacker News with the receipts. Positions and colors come from ESA’s GAIA DR3 release, a survey of 1.8+ billion stars. A Python script pre-renders those stars into custom skybox images so the backdrop is actual survey data, not a painted texture.

  1. The near field is real. Within about 17.72 parsecs (57.8 light-years), the map plots 53,836 stars from GAIA. Named waypoints match the book and film: Tau Ceti, Alpha Centauri, Sirius, Barnard’s Star, Wolf 359, and the rest. Val confirmed on HN that the featured stars reflect known science. Astrophage routes are fiction layered on top.

  2. Two views, two purposes. Color mode shows star colors from GAIA photometry. Petrova mode overlays the astrophage infection path from the story (Val credits David A. Wheeler’s writeup for getting that arc right). You can appreciate the fan detail and still trust the stellar positions underneath.

  3. The skybox pipeline is the technical flex. You cannot ship 1.8 billion points to a browser tab and expect smooth orbit controls. Val’s approach: offline Python rendering into image tiles, then load the result as the all-sky backdrop labeled “Gaia DR3 All-Sky.” A handful of very bright stars missing from the cut get handled separately. Smart preprocessing beats brute force.

  4. Zero setup, heavy GPU. Open the URL, pick a destination star, drag to rotate. An About modal on the site covers credits and data sources. No account, no install. On older hardware the 3D view may stutter. This is a demo, not a planetarium app.

  5. Val shipped a bigger follow-up. If you want more than the Hail Mary route, Gaia Atlas adds dozens of named stars, exoplanet systems, shareable travel links, and 600k stars rendered in-browser. GAIA Mary is the focused fan piece; Gaia Atlas is the sandbox.

First run

  1. Open valhovey.github.io/gaia-mary.
  2. Click About for the data blurb and credits.
  3. Select a destination (Tau Ceti is the default story endpoint).
  4. Toggle Color vs Petrova to compare science view and plot view.
  5. Drag to rotate; click named stars in the list to jump.

Want to build your own thing? Start at the GAIA DR3 archive. Val’s HN comment is basically an invitation: the dataset is public, the rendering problem is interesting, and fan projects do not need a lab badge.

Worth your time if: you read or watched Project Hail Mary and want to see local stellar space with real coordinates, or you are looking for a weekend open-data project with a gorgeous payoff.

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