Blue and green sight lines run from opposite ends of Earth's orbit to the star. Star depth scales with 1/p so a larger parallax pulls the star closer on the teaching stage.
Angles are exaggerated for the camera - real stellar parallaxes sit below one arcsecond. This isolates the measurement triangle Solar System 3D Explorer does not teach.
Parallax Distance 3D Explorer
See how Earth's 1 AU orbit baseline turns a tiny parallax angle into stellar distance - d (pc) = 1/p (arcsec), with 1 pc about 3.26 ly (about 206,265 AU) and Proxima Centauri at about 0.7687 arcsec.
Drag to orbit the view, scroll or pinch to zoom, and try Proxima, 1 arcsec, and 0.5 arcsec presets. Formula and Earth baseline buttons fill the facts panel with the same figures shown above.
- Sun plus Earth at opposite orbit ends as the teaching baseline
- Sight lines to a distant star that move with parallax presets
- Proxima Centauri preset at about 0.7687 arcsec
- 1 arcsec = 1 parsec and 0.5 arcsec = 2 pc literacy buttons
- Distinct from Stellar Magnitude Scale Explorer and Milky Way Map 3D Explorer
- Runs fully in the browser with the vendored three.js engine - no account, no upload
Teachers use it to show why one arcsecond defines one parsec, students scrub Proxima versus 1 arcsec, and curious readers connect a tiny angle on the sky to a light-year distance without opening a catalog alone.
| Quantity | Value | Source |
|---|---|---|
| Parallax distance | d (pc) = 1 / p (arcsec) | Definition of the parsec |
| 1 parsec | about 3.26 ly | Standard conversion |
| 1 parsec in AU | about 206,265 AU | 1 / tan(1") geometry |
| Proxima Centauri parallax | about 0.7687 arcsec | Published Proxima p (Hipparcos/Gaia era summary) |
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 visualization - sight-line angles are exaggerated so the triangle stays readable. It is not a Hipparcos or Gaia reduction pipeline or a precise ephemeris. Proxima Centauri at about 0.7687 arcsec is a teaching preset, not a live catalog query.
For a step-by-step walkthrough, read the Parallax Distance 3D Explorer step-by-step guide. When you need session fit and limits, see when to use Parallax Distance 3D Explorer. The Space 3D collection also includes a Stellar Magnitude Scale Explorer for brightness scales and a Milky Way Map 3D Explorer for galactic structure.
Frequently Asked Questions
What does Parallax Distance 3D Explorer show?
Earth at opposite ends of a 1 AU orbit, sight lines to a star, and how changing parallax in arcseconds moves the star with distance d = 1/p in parsecs.
What is the parallax distance formula?
d (pc) = 1 / p (arcsec). A star with parallax 1 arcsec sits at 1 parsec; 0.5 arcsec sits at 2 pc.
How far is one parsec?
About 3.26 light-years, or about 206,265 AU - the distance where Earth's orbit subtends one arcsecond.
What about Proxima Centauri?
Its published parallax is about 0.7687 arcsec, which implies about 1.30 pc (~4.24 ly) with d = 1/p.
How is this different from Stellar Magnitude Scale Explorer?
Stellar Magnitude Scale Explorer teaches apparent vs absolute brightness. Parallax Distance 3D Explorer isolates the Earth-baseline triangle that measures distance.
Are the on-screen angles true to scale?
No. Real stellar parallaxes are below one arcsecond, so the teaching stage exaggerates the triangle so the geometry stays readable.