AstrodleDiscover one real cosmic object every day
Astrodle is a free daily astronomy game. Once every UTC day you make a single discovery — one real, catalogued object from the known universe, drawn just for you and locked in for good. No re-rolls and no sign-up to start: open Astrodle, make your daily draw, and see what the universe hands you.
◆ Daily draw · Locked once
One discovery per day ◆ No re-rolls
Every discovery is a real, catalogued astronomical object — a star, exoplanet, pulsar, nebula, galaxy, black hole or a body of our own Solar System.
◆ Today's best discovery
discovered by cosmic-draco-n9g
01 // How it works
Every game of Astrodle runs on the same three beats: one irreversible draw, one real object to meet, and a rarity you can actually explain. Here is what happens each day.
- 01
Make your daily draw
One button, once per UTC day. The draw is a pure function of your anonymous id and the date, so it can never be re-rolled.
- 02
Meet a real object
Your discovery appears as a data-inspired illustration with its name, type, four family-appropriate facts and a time-capsule line placing it in history.
- 03
Read its rarity
A coloured family tier headlines the result. Then badges reveal one at a time — measured traits and well-established class facts — adding up to your Discovery Points.
02 // The daily loop
One draw a day
Astrodle borrows its rhythm from once-a-day number games like RNGdle, then swaps the random number for a real, cited astronomical record. You get one discovery per UTC day and the result is readable at a glance — a data-inspired illustration, a name, an object type and four facts chosen to suit that kind of object.
Results that accumulate
Every discovery adds its badge scores to a lifetime Discovery Points total, and each result has its own share card and permalink. Play anonymously and your seven most recent discoveries stay on the device you played on. Create a free account — an email and a 6-digit code — and your full history follows you across devices, your discoveries can land on the daily, weekly and all-time leaderboards, and you can add friends and heart other people's finds.
03 // What you might discover
Discoveries are drawn from eight families of catalogued objects. The draw picks a family by its published probability, then an object you have not seen from your personal non-repeating deck for that family.
- Stars
- Main-sequence dwarfs, red giants, supergiants, Wolf–Rayet and carbon stars, and white-dwarf remnants.
- Exoplanets
- Confirmed worlds orbiting other stars, from scorched hot Jupiters to temperate sub-Neptunes.
- Neutron stars & pulsars
- The collapsed cores of dead stars — radio pulsars, millisecond pulsars and magnetars.
- Nebulae & H II regions
- Clouds of gas and dust between the stars, including supernova remnants and dark nebulae.
- Star clusters
- Open and globular clusters — gravitationally bound families of hundreds to millions of stars.
- Galaxies, AGN & quasars
- Spiral, elliptical and irregular galaxies far beyond the Milky Way, and their active nuclei.
- Black-hole systems
- X-ray binaries and other systems where the mass of a black hole has actually been measured.
- Solar System bodies
- Planets, moons, dwarf planets, asteroids and comets of our own system.
The full odds table and catalog sizes are on the methodology page.
04 // The honesty contract
Every result is a real record shown only as specifically as its source supports. Values that are measured, derived or estimated stay labelled as such. The artwork is a data-inspired illustration built from the catalogue record — never a photograph passed off as real. “Rarity” describes Astrodle’s released catalog and draw rules, not the real abundance of anything. Read the full contract.
In this version Astrodle ships only procedurally drawn illustrations, each generated from the object’s own catalogue numbers and labelled “Data-inspired illustration — not a photograph”. Observed survey imagery for the brightest objects is a later release. Where a value is unknown, Astrodle says so rather than filling the gap.
05 // Questions
What is Astrodle?
Astrodle is a free daily astronomy game. Each day you make one discovery: a single real, catalogued astronomical object. It borrows the once-a-day locked loop from number games like RNGdle, but replaces the random number with a genuine cited astronomical record.
How often can I play?
Once per UTC day. There are no re-rolls, no purchases and nothing to unlock. The next discovery becomes available at 00:00 UTC.
Are the objects real?
Yes. Every result exists in a published astronomical catalog and is shown with its source. Measured, derived and estimated values stay distinguishable, and related phenomena are never relabelled as the object itself — a quasar is not shown as a black hole. See the honesty contract.
Where does the data come from?
A curated, versioned catalog built from published surveys and databases — Gaia, the NASA Exoplanet Archive, the ATNF Pulsar Catalogue, OpenNGC and others — federated through SpaceCatalog. No live astronomy API is called while you play. Full list on the sources & licenses page.
How is rarity decided?
Two layers. The family tier is the coloured headline and tracks the published draw odds. Each badge is scored by its own frequency, measured by simulating tens of millions of draws over the catalog. The methodology page publishes the odds and the formula.
Do the odds reflect how common these objects really are?
No. The family odds are hand-designed so the game stays varied — a uniform draw would return a faint star or galaxy almost every day. “Catalog rarity” describes Astrodle’s released pool and draw rules only, never the true cosmic abundance of an object type.
Do I need an account?
Not to play. Anonymous play needs only one cookie: a discovery per day and your seven most recent results, kept on that device. A free account (an email plus a 6-digit code) is optional — it carries your history across devices and puts your discoveries on the leaderboards. See privacy for what each mode stores.
Is Astrodle free?
Yes. Astrodle is completely free — no ads, no paywalls, nothing to buy, and accounts are free too. It runs in your browser and installs as a lightweight PWA if you want a home-screen icon.
Does Astrodle work on mobile?
Yes. Astrodle is built mobile-first and runs in any modern browser on phone, tablet or desktop. You can add it to your home screen and open it like an app.
Can I play Astrodle offline?
The daily draw needs a connection, but once a discovery is made Astrodle keeps it — and your recent history — available offline.
How do I share my discovery?
Every Astrodle result has a Share button that copies a short summary plus a permalink with its own preview image, in the same “-dle” format as other daily games.
I found a wrong fact — how do I report it?
Email the details via the contact page. Point to the object and the source you are checking against; corrections are rolled into the next catalog release.
Is Astrodle affiliated with NASA or ESA?
No. Astrodle is an independent project. It cites public data from surveys and archives including the NASA Exoplanet Archive, Gaia and the ATNF Pulsar Catalogue, but is not endorsed by any of them.
06 // About Astrodle
Astrodle is an independent project built on a curated, versioned catalog federated through SpaceCatalog, drawing on Gaia, the NASA Exoplanet Archive, the ATNF Pulsar Catalogue, OpenNGC and others. Every release pins its data by checksum, so a discovery you share today will still show the same facts and the same sources months from now. Astrodle is a working title and the game is still evolving — the daily loop is stable; public results, an events calendar and more object families are planned.