Space Time
A free 3D solar system simulator in your browser
Space Time is an interactive 3D solar system you can fly through. Visit a planet or moon, look around from the surface, or move the clock to see where everything was on another date. It is free and runs in your browser.
🚀 Open the 3D solar system Free · No account · No download · Any modern browser
Follow a story. Keep a discovery.
Explore new destination stories and build your own collection of views, evidence and notes.
More ways to explore and understand
New tools connect the view, its evidence and your next discovery.
See it move
These clips show Saturn's measured rings, a continuous journey from Earth to the Coma Cluster, the Sun, Sagittarius A*, and mapped local-universe structure.
🎬 Every clip uses Space Time's own engine frames. No stock footage, generated astronomy or external cutaways.
Move around the solar system
The planets are placed from the same ephemeris data used by the planetarium. You can move the camera freely, follow an orbit, or pull back to see real distances.
🪐 Every planet and moon
Mercury through Neptune with real surface maps, plus Pluto, Ceres and Eris. The major moons are full 3D worlds you can go to and stand on, and every named moon is searchable, down to the small irregular ones.
🛰️ Fly anywhere
Double-click a planet to glide to it, orbit it with the mouse or a pinch, then drop onto the surface and look up at its sky. Zoom all the way out and the whole solar system, asteroid belt and all, sits in front of you.
⏱️ Travel through time
The clock scrubs forward and back through any date. Speed it up and the planets sweep along their orbits, with conjunctions, oppositions and retrograde loops playing out the way they really do.
☀️ Real positions, real orbits
Nothing here is faked or evenly spaced. Planet positions come from the Astronomy Engine library, tested to within about one arcminute, on elliptical orbits with real inclinations. Sizes and distances are at true scale.
🪨 The real asteroid belt
The brightest several thousand numbered asteroids from JPL, placed where they actually are: the true main belt between Mars and Jupiter, with the Jupiter Trojans bunched ahead of and behind the planet. Search Ceres, Vesta or Pallas to go to one.
🌌 Keep zooming out
The solar system is just one stop. Pull back through the nearest stars to the Milky Way, then out to 43,500 real galaxies and the cosmic web, all on one continuous zoom from the ground to the edge of the observable universe.
What this solar system simulator calculates
Pick any date and Space Time works out where each planet is, then draws the scene from wherever you put the camera. Planet positions come from Astronomy Engine, which uses the VSOP87 and NOVAS models and is tested against JPL Horizons to within about one arcminute. Moons, dwarf planets, comets and asteroids follow published orbit data.
It is a calculated model, not a physics sandbox. You cannot change a planet’s mass, add a new world or set up a collision. For the full list of what is calculated and what is not, read what the universe simulator calculates.
A digital orrery you can step inside
A mechanical orrery shows the planets turning around the Sun on gears. This interactive solar system model does the same with real orbits and real dates. Speed up the clock to watch Mercury lap the inner system, or stop on tonight’s date and see why Mars and Saturn appear where they do. Planet sizes and distances are at true scale, so zooming out shows how empty the solar system really is.
See the solar system as it is right now
Open it and the planets are already where they belong for this moment. A few of the places a 3D solar system can take you.
Turn the Voyager journey into a light-travel-time exercise with the printable Voyager signal-delay activity. It uses computed distance and light time, not live communication telemetry.
Open it from any device
The same page works on desktop, tablet, and phone, and a shared link opens the view directly.
Nothing to install
No app, no setup, no platform choice. Open the page and it runs. Send the link and the other person is looking at the same 3D solar system a second later, no install on their end either.
Accurate, not a toy
Flat solar-system diagrams put the planets in a tidy row at made-up distances. Here the orbits, distances and current positions are real, so what you see actually matches the sky.
Great for learning
Labels, orbit paths and real distances make it a clear 3D solar system for a class or for your own curiosity. Search any planet, moon, comet or asteroid by name to go straight to it.
Small worlds, remarkable detail
Visit Lucy’s asteroid pair, Arrokoth, mission-mapped moons and irregular small bodies. These views use observed maps and shape reconstructions; coverage limitations are explained in the app.
FAQ
Is this a real 3D model of the solar system?
Yes. The planets, major moons, dwarf planets and brightest asteroids are placed where they actually are, on their true elliptical orbits, with planet positions calculated by the Astronomy Engine library. It is a working model you fly through, not a flat diagram.
Is it free?
Yes. Free, no account, nothing to install. It runs in any modern browser.
Can I see where the planets are right now?
Yes. It opens at the current moment, and you can scrub the clock to any date to watch the planets move, or jump to a date that matters to you.
Is it scientifically accurate?
Planet positions are tested against JPL Horizons and NOVAS to within about one arcminute, which is far finer than you can see by eye. Sizes and distances are at true scale.
Does it run on my phone?
Yes. The same build runs on desktop, tablet and phone, with touch controls to orbit, pinch to zoom and tap a planet to go to it.
Is this a solar system simulator?
Yes, in the sense of a calculated model. Space Time works out where each planet is for any date and draws the solar system from that viewpoint, so you can watch orbits, conjunctions and retrograde motion play out. It does not run a gravity sandbox: you cannot change masses, add planets or collide worlds.
Can I see where the planets were in the past or will be in the future?
Yes. Move the clock or type a date and the planets move to their calculated positions for that moment. You can also speed time up to watch years of orbital motion in seconds.
Is the solar system shown to scale?
Yes. Planet sizes and orbital distances use real values in one continuous space, so the planets look tiny from far away. Labels and markers help you find them; they are not part of the model.
Choose a world to explore
Use the simulation clock to change the date and compare positions. Zoom changes your viewpoint; close views make individual worlds readable, while the wider scene preserves their spatial context. These guides explain the observations and limitations behind each destination.