Scrub through a synodic month and watch the Sun-Earth-Moon geometry set the lit fraction on the Moon - the facts panel names each phase and lists the real orbital figures.
The phase slider runs from day 0 to 29.53 of the synodic month - the interval between successive new moons - and a play button animates one full cycle in about 30 seconds at 1x.
On-screen sizes and distances are compressed so the Sun, Earth, and Moon fit one view; the panel table carries the real published figures from NASA.
Moon Phases 3D Explorer
Scrub through a synodic month and watch the Sun-Earth-Moon geometry set the lit fraction on the Moon.
Drag to orbit the view, scroll or pinch to zoom, and slide the phase day control from 0 to 29.53 to step through new moon, first quarter, full moon, and back.
The facts panel names each phase and lists real orbital figures - synodic month 29.53 days, sidereal month 27.32 days, mean distance 384,400 km, and orbital inclination 5.14 degrees.
- Phase slider from day 0 to 29.53 of the synodic month with a live phase name in the panel
- Play button animates one full lunar month in about 30 seconds at 1x
- Sun, Earth, and Moon shown as a geometry lesson - Lambert shading shows the lit hemisphere
- Real published figures in the panel; on-screen layout is compressed and disclosed
- Runs fully in the browser with the vendored three.js engine - no account, no upload
Teachers use it to show why a crescent sits low at dusk, students compare sidereal vs synodic month length, and curious readers pause on full moon to read the 384,400 km mean distance.
| Quantity | Published value | Source |
|---|---|---|
| Synodic month (new moon to new moon) | 29.53 days | NASA Moon Fact Sheet |
| Sidereal month (orbit vs stars) | 27.32 days | NASA GSFC eclipse site |
| Mean Earth-Moon distance | 384,400 km | NASA Moon Facts |
| Orbit inclination to ecliptic | 5.14 degrees | NASA Moon Fact Sheet |
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 tuned to teach phase geometry - it does not compute an ephemeris or n-body gravity. Starting angles are set by the slider, not by today's date.
For a step-by-step walkthrough, read the Moon Phases 3D Explorer step-by-step guide. The Space 3D collection also includes a Solar System 3D Explorer and an Earth 3D Globe with a live day-night line.
Frequently Asked Questions
What does the Moon Phases 3D Explorer show?
Scrub through a synodic month and watch the Sun-Earth-Moon geometry set the lit fraction on the Moon - the facts panel names each phase and lists the real orbital figures.
Are the sizes and distances to scale?
On-screen sizes and distances are compressed so the Sun, Earth, and Moon fit one view; the panel table carries the real published figures from NASA.
Is this a physics simulation?
The scene is an educational visualization tuned to teach phase geometry - it does not compute an ephemeris or n-body gravity. The copy never claims a physical simulation.
What real figures does the panel include?
Synodic month 29.53 days, sidereal month 27.32 days, mean Earth-Moon distance 384,400 km, and orbital inclination 5.14 degrees - all from NASA published fact sheets.
How do I step through the phases?
Drag the phase day slider from 0 to 29.53, or press Play month to animate one full synodic cycle in about 30 seconds at 1x.