gcdatlas
An explorable atlas of the real universe, drawn entirely in ASCII characters.
Live at gcdatlas.com.
Fly from a city street's worth of sky to the edge of the observable universe in one smooth zoom. Planets are where they are today, about 2,000 naked-eye stars sit at their measured distances, and every active satellite circles the Earth in real time.
More light means a denser character. Colour comes from the physics: the temperature of a star, the glow of hot gas, the shift of light from things moving fast. Positions, distances and sizes are real; the look of each object is a physically based artist's rendering (how accurate is it?).
No sign-up, nothing to install. It runs in any modern browser, on a desk or a phone.
What's new? See the patch notes (short, for visitors) or the changelog (every detail). The latest: launches you can hear, under the real weather of the pads; Pip takes the stage.
140 places to visit (more to come...)
Black holes bend light above the true shape of their curved space. Galaxies collide, binary stars trade gas, a star is torn apart, and two black holes merge and ripple spacetime.
The Halo
One thing here is invented: the Halo, a long-range cruiser with a captured star for a heart. It roams the atlas on its own, about two minutes at each place, then crosses space at light speed or folds itself into embers and forms again somewhere else. Follow behind it, or ride along from its bridge.
Riding behind the Halo as it jumps to light speed and drops out beside the Moon.
- A move for every place. Through Saturn's Cassini Division, low over Jupiter's Great Red Spot, through a star's corona, through the hole of a ring nebula.
- Jobs. A hologram scan that names real features with real numbers, a refuelling skim just above a gas giant's clouds or a star, and a weapons test: an attack run that fires a railgun straight along its heading.
- Pip, the Halo's little two-eyed drone, is out for most of every stay. It plays peekaboo at the edge of your view, rides beside you, sits on the bow, and becomes the heart of the railgun.
- Ride along. The camera keeps the place in view behind the ship and glides between angles, or holds still if you prefer.
- The Halo tour. Flip the "Halo tour" switch beside tours and ride along while the Halo flies any tour's stops.
SpaceX launches
Starship, Falcon 9, Falcon Heavy and Crew Dragon stand on their real pads at Starbase, Cape Canaveral and Vandenberg. Pick one and watch it launch by day, about 3 minutes a flight with one smooth camera, or press "real speed" to see every second. The Starship booster flies back and is caught by its tower. Real launches play live at their scheduled time.
Picking a rocket brings the camera down from space onto its pad in one smooth move. You hear the launch (the roar arrives at the speed of sound) and see its smoke drift in the real wind, under the clouds and haze the weather at the pad has today.
The ground round the pads is real: aerial photos (Starbase as of January 2026), satellite images, the height of the land and the buildings. And Starman still drives his Tesla Roadster round the Sun, shown where he really is today.
Things to do
- The atlas. Search or browse every place by kind, distance, size or name, and see which ones you have not visited yet. Search knows catalogue numbers too, such as M31 or NGC 1976.
- Random tour. 12 places from the whole atlas, a new mix each time, the ones you have not seen first.
- Earth's story. 4.54 billion years on one slider: magma ocean, snowball Earth, the first forests, the asteroid, today.
- Scale ladder. Drag one marker from the Moon to the observable universe; let go near a name to fly there.
- Flybys past the giants (the Sun, UY Scuti, TON 618, the Milky Way) that show just how big they are.
- Time machine. Run the Solar System forwards or back, or watch the constellations drift over 200,000 years.
- Live Earth. Every active satellite at its real position, and the next rocket launches at their pads.
- Screensaver (
Z). Full screen, the interface fades, and an endless shuffled tour plays with the music.
- Photo mode (
P). Frame a shot, then save it as a picture or copy it as ASCII text.
- Today's discovery. One object a day, the same for everyone, with a streak to keep.
- Collection log. Ticks off what you have seen and hands out badges.
- Music. gcd radio: 15 songs in six styles, from ambient and ambient piano to lofi and synthwave, made live in your browser. Pick a mood (mix, calm, beats, groove), skip a song or pick one from the list.
- What's new. The button beside ? lists what changed in each version.
- Share. A link takes a friend to your exact view, tour and date.
- Private. Your settings, location and progress stay on your device.
On your phone
A thumb-sized dock, an info card you can swipe away, and pinch to zoom. Works upright and on its side.
In the future
These are plans and ideas, not promises. They will land one at a time.
- Earth, closer. The launch sites have real ground now; next, more detail everywhere as you fly down: iconic cities and landmarks, mountains, rivers and deserts, all still drawn in ASCII.
- More from the Halo. New looks, new jobs and new effects for the ship, and more ways to ride along.
- Explore for yourself. If it can be done well: land on worlds and look around, a little like No Man's Sky, in text.
- More destinations. New stars, nebulae, galaxies, exoplanets and spacecraft.
- Quality of life. Smoother controls, clearer menus and a calmer phone layout.
Controls
| Input | Action |
|---|
| drag | orbit the camera (in your sky: look around) |
| scroll / pinch / + - | zoom |
| right-drag / shift-drag | pan |
| click or tap | fly to an object; once there it loops through its best angles until you take the camera |
/ | search |
[ ] | previous / next tour stop |
| W A S D, R F | fly freely |
| space or ❚❚ / ▶ (top right) | pause or play: the tour, or the angle loop of an object you picked |
| esc | close panels, then free camera |
| V · Y · T | detail · travel speed · time speed |
| G · L · M | glow · labels · music |
| Z · P · B | screensaver · photo mode · your sky |
| H · ? | home · help |
Data and credits
- Star positions and parallaxes: Hipparcos, via star-catalog-lite; colours, constellation lines and the Milky Way outline: d3-celestial by Olaf Frohn
- Earth's coastlines: Natural Earth via world-atlas
- Planet orbits: JPL approximate Keplerian elements; body orientations: IAU WGCCRE
- Satellites: CelesTrak general perturbations data; launches: The Space Devs Launch Library 2
- The ground round the launch sites: NOAA NGS and USDA NAIP aerial photos, Copernicus Sentinel-2 satellite images, AWS Terrain Tiles, buildings © OpenStreetMap contributors; the weather there: Open-Meteo
- Object facts and measurements: NASA, ESA, ESO and the published literature (see docs/ACCURACY.md)
