Select a body to keep it centered on screen while the simulation continues.

About This Simulation

Developed and created by Tom Wellborn, 2026.

This is a compact, interactive solar system experience designed to make the major motions and scale relationships readable on a normal screen without losing the feeling of space.

You can move freely through the scene, follow planets and moons, inspect objects, and change time so you can watch the system evolve from calm real-time motion to accelerated orbital choreography.

• Planet and moon sizes are drawn from a shared size scale relative to the Sun, so body diameters stay visually meaningful.
• Planet positions now follow date-based JPL approximate heliocentric positions, letting the model reflect where the planets should be for the chosen simulation date and time.
• Faint orbital rings act as visual guide tracks for compacted planet and moon paths, so you can read motion and ordering without mistaking them for literal physical bands in space.
• Moons now use date-based mean-motion positions as well, so changing the simulation date re-creates the same moon geometry for that moment.
• The scene now uses a curated local texture set for the Sun, major planets, and selected showcase moons, while smaller bodies can fall back to the procedural renderer so the view stays readable and visually consistent.
• Sun-driven illumination is now stronger, and object cards can report an Earth-view phase estimate for bodies where the geometry is available.
• A built-in event feed can flag transits, eclipses, and occultation-style alignments for major moons with lightweight predictive timing, then hold the current readout long enough to be readable.
• A staged startup warmup now loads the Milky Way, Sun, and core planet assets behind a dedicated loading overlay so the scene feels ready before you begin interacting.
• Very small smartphone-sized viewports are intentionally blocked with a larger-screen message, so the simulation does not try to render into an unreadable layout.
• Hover and click cards show object facts, distances, orbital timing, follow actions, quick links to learn more, and panel info buttons that explain how to read the displays.
• Camera controls support drag, zoom, follow mode, recentering, a draggable date timeline, a Live Now real-time toggle, and touch-friendly navigation on phones and tablets.
• The simulation remembers your preferred view, speed, labels, music, units, and other settings between sessions unless you clear them.

Some parts remain intentionally simplified for readability: orbit spacing is compressed to fit the screen, the faint orbital rings are guide paths rather than literal spatial widths, and Pluto stays on the simplified model path.

More Info

This simulation is built as an HTML5 browser app, using a single canvas-based scene with JavaScript for interaction, motion, rendering, and state management. It is designed to run directly in a modern browser without requiring extra software.

The visual scene combines local image assets with live browser rendering. Camera movement, labels, info cards, music, touch support, saved settings, and staged startup warmup all run in the browser so the project stays easy to open, share, and publish.

• Core technology: HTML5, CSS, JavaScript, the Canvas 2D API for the scene, and the Web Audio API for the ambient soundtrack.
• Planet positions: date-based heliocentric planet placement uses JPL approximate position formulas so the major planets can be shown at realistic locations for the chosen simulation date. These positions are computed locally in the browser from embedded reference data, not fetched live. The Live Now control snaps that same model to the current real moment, then can toggle back to your prior simulation state.
• Moon positions: date-based moon placement uses JPL planetary satellite mean-element epochs and mean anomalies as lightweight browser-friendly anchors for recreating moon geometry by date. These moon positions are also computed locally from stored reference values rather than requested from JPL or NASA on each change.
• Sizes, periods, and orbital values: body diameters, periods, and other baseline numbers are drawn from NASA and JPL fact-sheet style references used throughout the model data.
• Orbital guide rings: the faint circles and moon-path rings are visual orbit guides inside the compact layout. They show where bodies travel in this readable 2D model, but their apparent line thickness and spacing are not meant to be literal scale measurements.
• Object imagery: local body images are sourced from Wikipedia article imagery and then stored in the project for scene rendering and cards. The scene renderer now uses a curated subset for the Sun, major planets, and selected moons, while other bodies can stay on the procedural shader for consistency.
• Illumination and phases: scene bodies use Sun-driven lighting in the top-down model, and object cards can show a lightweight Earth-view phase estimate based on the current locally computed body geometry.
• Milky Way background: the galaxy panorama comes from ESO imagery and is used as the real-space backdrop behind the simulation.
• Startup warmup: the app now preloads the Milky Way, the Sun, and the core planet/dwarf-planet scene assets before unlocking interaction, then continues warming minor moon images in the background.
• Minimum practical screen size: very small smartphone-style viewports are blocked intentionally and shown a larger-screen message instead of trying to force the full simulation into an unreadable render.
• Event feed: eclipse, transit, and occultation-style notices are generated from simplified Sun/Earth alignment geometry around each parent planet, then cadence-smoothed into a readable current/next display instead of re-sorting every frame.
• Modeling note: distances are intentionally compacted on screen for readability, so the simulation preserves useful relationships without requiring an impossible amount of display space.
• Context help: small info buttons on the main menu, object card, and scale guide open concise explanations of what each panel means and how to read it.

The result is a browser-friendly educational model that mixes real astronomical reference data with readable visual design choices, so it can feel informative without becoming too dense to explore.