Compare the conservative liquid-water habitable zone around stars of different luminosity - the green annulus moves inward as L drops, following r_HZ proportional to sqrt(L/Lsun).
At L=1 the conservative HZ is roughly 0.95-1.37 AU (Kopparapu-style, NASA-cited). Earth at 1 AU sits in the band; Venus at ~0.72 AU is inside; Mars at ~1.52 AU is near the outer edge.
Drag to orbit the view and scroll or pinch to zoom. Click the star, green HZ band, or planets for the facts panel. Pause orbits freezes the slow markers.
Habitable Zone 3D Explorer
Compare the liquid-water habitable-zone annulus around the Sun, a cool M dwarf, and a TRAPPIST-1-class ultracool star - see how the green band shrinks inward as luminosity drops, following r_HZ proportional to sqrt(L/Lsun).
At solar luminosity (L=1) the conservative habitable zone is roughly 0.95-1.37 AU per Kopparapu-style estimates cited by NASA exoplanet education pages. Earth at 1 AU sits inside that band. Venus at ~0.72 AU is interior (too hot for surface liquid water today). Mars at ~1.52 AU is near or beyond the outer conservative edge.
Switch to an M dwarf (L=0.1) and the HZ moves to about 0.30-0.43 AU. TRAPPIST-1-class (L=5.5e-4) places the HZ near 0.022-0.032 AU - order-of-magnitude from sqrt scaling of the same 0.95-1.37 AU reference edges.
- Three star presets: Sun L=1, cool M dwarf L=0.1, TRAPPIST-1-class L=5.5e-4
- Conservative HZ annulus with inner 0.95 AU and outer 1.37 AU at L=1, scaled by sqrt(L)
- Sun preset shows Venus, Earth, and Mars at published semimajor axes
- Facts panel with HZ table in AU and sqrt(L) scale law
- Click star, HZ band, or planets; Pause orbits freezes slow orbit markers
- Runs fully in the browser with the vendored three.js engine - no account, no upload
Astronomy students see why dim stars host planets much closer in, exoplanet readers compare TRAPPIST-1 HZ distances to the solar case, and curious visitors get a one-screen map of the goldilocks annulus.
| Star | L (Lsun) | Conservative HZ (sqrt scale) |
|---|---|---|
| Sun | 1 | 0.95 - 1.37 AU |
| Cool M dwarf | 0.1 | ~0.30 - 0.43 AU |
| TRAPPIST-1-class | 5.5e-4 | ~0.022 - 0.032 AU |
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 with compressed orbital spacing for one-screen teaching - it does not run a full climate or atmospheric model, and HZ edges follow the sqrt(L) scaling from Kopparapu-style conservative bounds at L=1 rather than per-star bespoke climate integrations.
For a step-by-step walkthrough, read the Habitable Zone 3D Explorer step-by-step guide. The Space 3D collection also includes the Exoplanet Transit 3D Explorer for how we detect planets, and the Star Lifecycle 3D Explorer for how stellar luminosity evolves.
Frequently Asked Questions
What does the Habitable Zone 3D Explorer show?
The conservative liquid-water habitable zone as a green annulus around the Sun, a cool M dwarf, or a TRAPPIST-1-class star - with HZ radius scaling as sqrt(L/Lsun) from Kopparapu-style edges 0.95-1.37 AU at L=1.
What is the Sun conservative habitable zone?
Roughly 0.95 AU (inner) to 1.37 AU (outer) at L=1, using Kopparapu-style conservative bounds cited in NASA exoplanet education materials. Earth at 1 AU sits inside; Venus at ~0.72 AU is interior; Mars at ~1.52 AU is near the outer edge.
How does HZ radius scale with luminosity?
r_HZ proportional to sqrt(L/Lsun). A star ten times dimmer (L=0.1) places the HZ about sqrt(0.1) = 0.316 times closer than the solar case. TRAPPIST-1-class (L=5.5e-4) yields HZ near 0.022-0.032 AU from the same scaling.
Where do the numbers come from?
Reference edges 0.95 and 1.37 AU at solar luminosity follow Kopparapu-style conservative habitable-zone estimates used in NASA exoplanet outreach. Planet distances for the Sun preset use published semimajor axes (Venus 0.72, Earth 1.00, Mars 1.52 AU).
Is this a climate model?
No. It is an educational visualization that draws a sqrt(L)-scaled HZ annulus with compressed orbital layout for one-screen teaching. It does not integrate atmospheres, greenhouse gases, or stellar spectra.
Can I compare different star types?
Yes. Preset buttons switch among Sun (L=1), cool M dwarf (L=0.1), and TRAPPIST-1-class (L=5.5e-4). The facts panel lists conservative HZ edges in AU for each preset.