# Mzu 3D Solar System

> A free, browser-based 3D Solar System explorer with first-person expeditions to eight worlds. No download, account, or AI service is needed.

## Start here

- [Solar system 3D simulator](https://www.3dsolarsystem.net/): Rotate, zoom and select the Sun, eight planets, moons and dwarf planets; follow a planet tour; switch artistic or real scale and speed; share, save or embed a view. Not a live ephemeris.
- [Explore space online in 3D](https://www.3dsolarsystem.net/space-explorer-guide.html): step-by-step guide to the controls, scale and speed menus, tour, expeditions and embedding.
- [Planet sizes and distances compared](https://www.3dsolarsystem.net/planet-sizes-and-distances.html): NASA diameters, distances, periods and a 1-metre-Sun scale model.

## Planet pages (3D view + facts + FAQ with NASA sources)

- [Mercury](https://www.3dsolarsystem.net/mercury.html): smallest planet; 88-day year, 176-day solar day, −180 °C to 430 °C.
- [Venus](https://www.3dsolarsystem.net/venus.html): hottest planet (~465 °C); spins backwards; a day is longer than its year.
- [Earth](https://www.3dsolarsystem.net/earth.html): 23.4° tilt and seasons; the Moon at 384,400 km.
- [Mars](https://www.3dsolarsystem.net/mars.html): red iron-oxide dust, thin CO₂ air, Olympus Mons, 687-day year.
- [Jupiter](https://www.3dsolarsystem.net/jupiter.html): largest planet, no solid surface, Great Red Spot, Galilean moons.
- [Saturn](https://www.3dsolarsystem.net/saturn.html): icy rings ~270,000 km across, density below water, Titan.
- [Uranus](https://www.3dsolarsystem.net/uranus.html): ~98° axial tilt, 84-year orbit, methane blue-green colour.
- [Neptune](https://www.3dsolarsystem.net/neptune.html): winds up to ~2,000 km/h, 165-year orbit, found by mathematical prediction.

## First-person expeditions (each page ends with a crawlable article: facts, discoveries, controls, science notes)

- [Walk on the Moon](https://www.3dsolarsystem.net/moon.html): walk and jump in lunar gravity (1.62 m/s²) under a black sky with Earth above the horizon; real NASA lunar module model.
- [Walk on Mars](https://www.3dsolarsystem.net/mars-expedition.html): 3.71 m/s² gravity, layered rock, dunes, butterscotch sky; real NASA rover model.
- [Walk on Venus](https://www.3dsolarsystem.net/venus-expedition.html): volcanic plain under a heavy orange sky at ~465 °C; Magellan orbiter overhead.
- [Walk on Mercury](https://www.3dsolarsystem.net/mercury-expedition.html): cratered plain, black sky, a Sun two to three times wider than from Earth, lobate scarp and hollows.
- [Descend into Jupiter](https://www.3dsolarsystem.net/jupiter-expedition.html): probe descent through ammonia clouds, a giant storm and the lightning layer.
- [Fly through Saturn's rings](https://www.3dsolarsystem.net/saturn-expedition.html): ring-plane cruise inside the Cassini Division at true ring proportions, beside NASA's Cassini model.
- [Fly through Uranus's rings](https://www.3dsolarsystem.net/uranus-expedition.html): narrow charcoal-dark rings of the sideways ice giant, beside Voyager 2.
- [Fly into Neptune's storms](https://www.3dsolarsystem.net/neptune-expedition.html): storm-layer flight toward a Great Dark Spot-style vortex, beside Voyager 2.

## Important limitation

This is an artistic educational visualization, not a live ephemeris or professional astronomy tool. Planet sizes and distances are compressed for visibility in every mode. Motion is compressed by default; the Speed menu switches to real orbital and rotation period ratios (display-capped at two turns per second). Expedition landscapes are science-inspired artistic reconstructions, not survey data.

## Useful capabilities

- Interactive mouse, touch, and keyboard-friendly exploration
- Focus links using `?focus=Earth` (replace Earth with another supported object)
- Embeddable view using `?embed=1`
- Downloadable canvas snapshot
- Basic radius, semi-major-axis, and eccentricity information for selectable planets, moons and dwarf planets (Pluto, Ceres, Eris, Makemake, Haumea)
- A visual asteroid belt, a Kuiper belt, rings on Jupiter, Saturn, Uranus and Neptune, a Halley-type example comet and a long-period example comet. Not a live catalog. High and Balanced quality also load shape models of Bennu and Itokawa; Low does not.
- Optional background music and an orbit-glow toggle. Quality is Auto, High, Balanced or Low.
- Facts follow the NASA Planetary Fact Sheet (https://nssdc.gsfc.nasa.gov/planetary/factsheet/) and NASA Science planet pages