Explore the cosmic distance ladder on a teaching log scale: 1 AU = 1.496e8 km, 1 ly = 9.461e12 km, 1 pc = 3.086e13 km (~3.26 ly), with parallax reach ~1000 pc.
1 AU = 1.496e8 km; 1 ly = 9.461e12 km; 1 pc = 3.086e13 km (~3.26 ly). Parallax teaching reach ~1000 pc; Cepheid period-luminosity is named as the next rung only.
Drag to orbit and scroll or pinch to zoom. Scrub the log slider, jump to AU / ly / pc, or play auto-zoom across the labeled rungs.
Cosmic Distance Ladder 3D Explorer
See how astronomers step from nearby solar-system distances to stellar and nearby-galaxy scales: 1 AU = 1.496e8 km, 1 ly = 9.461e12 km, and 1 pc = 3.086e13 km (~3.26 ly) on one continuous log zoom.
Parallax is reliable roughly to ~1000 pc on the Hipparcos/Gaia teaching scale used here. Beyond that, the next classic rung is the Cepheid period-luminosity relation - named on this page as the following step, not solved as a full distance pipeline.
Use the zoom scrubber to move the yellow marker along the scale bar, Jump AU / ly / pc for presets, Play zoom for a slow auto sweep, and Ladder table to restore the teaching figures.
- Earth marker at the AU end of the logarithmic ladder
- Labeled rings at 1 AU, 1 ly, 1 pc, ~1000 pc parallax reach
- Optional ~1 Mpc nearby-galaxy hint as a label-only outer rung
- Zoom scrub, Jump AU / ly / pc, play/pause auto-zoom
- Facts panel with conversion table and approximation honesty
- Runs fully in the browser with the vendored three.js engine - no account, no upload
Students compare AU, light-year, and parsec on one screen; astro readers place parallax before Cepheids; curious visitors get a honest log-scale picture instead of a fake Euclidean universe map.
| Feature | Figure | Source note |
|---|---|---|
| 1 AU | 1.496e8 km | IAU-style mean Earth-Sun distance |
| 1 ly | 9.461e12 km | Light-travel distance in one year |
| 1 pc | 3.086e13 km (~3.26 ly) | Parallax of 1 arcsec |
| Parallax reach | ~1000 pc | Hipparcos/Gaia teaching scale |
| Next rung | Cepheid P-L | Named step only - not a full solution |
Everything renders on your device with WebGL. The 3D engine loads once (about 0.7 MB) and is cached; no scene data is sent to a server.
The scene is an educational log-scale visualization - it is not a true universe simulation, and the ~1 Mpc ring is a label-only nearby-galaxy scale hint.
For a step-by-step walkthrough, read the Cosmic Distance Ladder 3D Explorer step-by-step guide. The Space 3D collection also includes Parallax Distance 3D and the Stellar Magnitude 3D Explorer.
Frequently Asked Questions
What does the Cosmic Distance Ladder 3D Explorer show?
A continuous log-scale zoom across teaching rungs: 1 AU = 1.496e8 km, 1 ly = 9.461e12 km, 1 pc = 3.086e13 km (~3.26 ly), plus a ~1000 pc parallax reach marker.
Where do the AU, ly, and pc figures come from?
1 AU = 1.496e8 km, 1 ly = 9.461e12 km, and 1 pc = 3.086e13 km (~3.26 ly) are standard teaching conversions used across astronomy courses.
Why ~1000 pc for parallax?
Parallax is reliable roughly to ~1000 pc on the Hipparcos/Gaia teaching scale used here. That marks where geometric parallax hands off toward standard-candle methods.
Does this page solve Cepheid distances?
No. Cepheid period-luminosity is named as the next ladder rung beyond parallax. The page does not claim a full distance solution or fit real Cepheid catalogs.
Is this a true universe simulation?
No. It is a teaching log-scale visualization with rings at log positions. The optional ~1 Mpc ring is a label-only nearby-galaxy scale hint.
How do I jump between rungs?
Use Jump AU, Jump ly, or Jump pc. Scrub Zoom for continuous log motion, or Play zoom for a slow auto sweep. Ladder table restores the conversion summary.